RNS Number : 4391B
Rainbow Rare Earths Limited
08 October 2020

8 October 2020

Rainbow Rare Earths Limited

("Rainbow" or the "Company")



Updated JORC Exploration Target

Rainbow Rare Earths Ltd is pleased to provide an updated JORC compliant Exploration Target for the Company's Gakara Project in Burundi ("Gakara") ("Exploration Target").

The Exploration Target defines clear strategy for modular development at Gakara targeting 10,000 - 20,000 tonnes per annum of rare earth concentrate production.

·   Initial Exploration Target covers nine high grade vein hosted areas of rare earth mineralisation containing 262,000 to 375,000 tonnes at a diluted grade of 7.0% to 12.0% total rare earth oxides ("TREO"), representing one of the world's highest rare earth grades

·   Simple, low cost exploration programme defined, with a budget of US$3.2 million, with the intent of upgrading the vein hosted areas to JORC compliant resources

·  If upgrade is successful, the resources are expected to be sufficient for development of a commercial scale mine at Gakara, initially targeting 5,000 tonnes per annum of rare earth concentrate production at an expected grade of 54% TREO

·  Technical study on the feasibility of a commercial scale operation will focus on a modular approach to development, capable of expansion to 10,000 - 20,000 tonnes per annum of rare earth concentrate

·  The Exploration Target is defined from only 10 of the 32 mineralised areas that have been identified by Rainbow to date - many other mineralised areas identified for future exploration can further expand the resource base

·  Further upside defined through breccia hosted mineralisation, with the Exploration Target containing 252,000 to 342,000 tonnes at 1.0% to 1.5% TREO, which could be developed as a parallel, lower grade processing stream

·    TECT Geological Consulting confirmed the presence of three large carbonatite bodies, which represent the regional source of rare earth elements, underpinning the scale of the potential at Gakara

George Bennett, CEO, said: "I have always believed in the long-term opportunity for the Gakara project to deliver a commercial scale operation into growing rare earth demand and rising prices.  The updated Exploration Target announced today is the first step on that path.  Over the next 12-18 months we plan to deliver the financing to execute our exploration strategy, upgrade our Exploration Target to JORC compliant resources, and complete a technical study on a modular development initially targeting 5,000 tonnes per annum of rare earth concentrate.

I am also pleased to announce that the work undertaken by TECT Geological Consulting in March 2020 not only increased the number of targets within our Mining Licence area, but also identified the presence of three large carbonatites which are the most likely source of the rich rare earth mineralisation within Rainbow's licence area.

Today's report has confirmed that the Gakara licence covers a highly prospective area with substantial high-grade mineralisation, based on the results achieved to date from both exploration and trial mining/processing.  Our long-term goal remains to develop, via a modular approach, 10,000-20,000 tonnes per annum of production, and realise the full value for our shareholders from downstream processing and separation to sell high value, separated rare earth oxides."

The Technical Report setting out the updated Exploration Target for the Gakara Project follows a systematic approach undertaken to understand the vast amount of historical data collected across the licence area.  This included historical data relating to Belgian era mining together with the results of Rainbow's activities.  The latter includes surface mapping and sampling, trial mining and processing, as well as the 2018 drilling programme and the most recently completed structural review and geophysical analysis led by TECT Geological Consulting.

The TECT study highlighted 36 Tier-1 and Tier-2 targets and 21 Tier 3 targets, increasing Rainbow's original 32 targets.  TECT also confirmed the presence of three large carbonatites on the Western area of the mining licence along a NNE- trending structure.  The southernmost carbonatite has a diameter of approximately 2.6 km.  These carbonatites are the most likely source of the rich rare earth mineralisation within the Gakara project area.

This work has resulted in a comprehensive exploration database which has allowed the updated JORC compliant Exploration Target to be defined.  The work has also delivered a clearly defined exploration programme to upgrade the Exploration Target and allow a formal technical study for the development of a commercial scale mine at Gakara to be delivered.

Gakara contains two styles of known mineralisation, locally termed vein hosted and breccia hosted.  Both mineralisation styles contain the same basket of rare earth minerals and produce an identical quality saleable concentrate. 

The updated JORC Exploration Target, quoted as a range of tonnes and grade, relates to nine vein hosted deposits and one breccia hosted deposit summarised below:


Lower estimate

Upper estimate






Vein Hosted Mineralisation





Murambi South




















Gomvyi Central





Gashirwe West and East















Vein Hosted Exploration Target





Breccia Hosted Mineralisation





Kiyenzi grade tonnage model





Kiyenzi depth extension





Kiyenzi lateral extension





Breccia Hosted Exploration Target





Note: The potential quantity and grade of the Exploration Target is conceptual in nature, there being insufficient exploration to estimate a Mineral Resource and that it is uncertain if further exploration will result in the estimation of a Mineral Resource. Numbers are rounded to appropriate levels commensurate with the level of accuracy of an Exploration Target. The Exploration Target was estimated as a range as required by the JORC Code (2012) and is based on data of varying quantity and quality, although is based largely on actual exploration, mining and processing results.

The bulk of the JORC Exploration Target relates to the vein hosted mineralisation, which is the focus of Rainbow's near-term growth strategy.  Vein hosted mineralisation is readily identified across the licence area by surface mapping and sampling; Rainbow's work to date has demonstrated that the Gakara Project is richly endowed with rare earth mineralisation.  However, this style of mineralisation is structurally complex, delaying the definition of JORC Mineral Resources.  A simple, low cost exploration programme has been defined to upgrade the vein hosted areas used in the Exploration Target, with a total budget of US$3.2 million, which is expected to be completed in 2021, subject to the Company raising the finance required.

In parallel with the exploration programme Rainbow will continue trial mining and processing bulk samples from across the licence area to confirm the mining methodology and demonstrate the expected uniformity of processing requirements.  Once the Exploration Target has been upgraded to a formal resource a technical study on a commercial scale operation will be completed.  This will initially focus on 5,000 tonnes per annum of rare earth concentrate, ensuring that the processing and other facilities are developed in a modular structure to allow growth to 10-20,000 tonnes per annum of concentrate production.

The Breccia hosted mineralisation will form a parallel, lower grade production strategy.  The near-term exploration strategy will also identify, from the results of the TECT geophysical study, areas of breccia hosted mineralisation for future resource definition.

Certain information contained in this announcement would have been deemed inside information for the purposes of Article 7 of Regulation (EU) No 596/2014 until the release of this announcement.



For further information, please contact

Rainbow Rare Earths Ltd


George Bennett

Pete Gardner

+27 82 652 8526


SP Angel Corporate Finance LLP


Ewan Leggat

Charlie Bouverat

+44 (0) 20 3470 0470


Notes to Editors:

Rainbow's focus is the Gakara Project in Burundi, which produces one of the highest-grade concentrates in the world (typically 54% Total Rare Earth Oxide) and is the only African producer of rare earths through the ongoing trial mining operations.  The Gakara basket is weighted heavily towards neodymium (Nd) and praseodymium (Pr), which account for over 80% of the value of the Gakara concentrate.

Nd and Pr are vital components of the strongest permanent magnets used for the motors and turbines driving the green technology evolution.  Analysts are predicting demand for magnet rare earth oxides will grow substantially over the coming years, driven by increasing adoption of green technology, pushing the overall market for Nd and Pr into deficit.

Competent Person's Statement

The Exploration Target was prepared by Mr Malcolm Titley, an employee of Maja Mining Ltd, in accordance with the Australasian Code for Reporting of Exploration Results, Mineral Resources and Ore Reserves, the JORC Code, 2012 Edition.  Malcolm Titley is a Competent Person as defined by the JORC Code 2012 Edition, having sufficient relevant experience to the style of mineralisation and type of deposits under consideration and to the activity for which he is undertaking.  Malcom Titley is a Member of both the Australasian Institute of Mining and Metallurgy and Australian Institute of Geologists.

Annexure 1: JORC Code, 2012 Edition - Table 1

Section 1: Sampling Techniques and Data

JORC Code explanation


Sampling Techniques

Nature and quality of sampling (eg cut channels, random chips, or specific specialised industry standard measurement tools appropriate to the minerals under investigation, such as down hole gamma sondes, or handheld XRF instruments, etc). These examples should not be taken as limiting the broad meaning of sampling.

Include reference to measures taken to ensure sample representativity and the appropriate calibration of any measurement tools or systems used.

Aspects of the determination of mineralisation that are Material to the Public Report.

In cases where 'industry standard' work has been done this would be relatively simple (eg 'reverse circulation drilling was used to obtain 1 m samples from which 3 kg was pulverised to produce a 30 g charge for fire assay'). In other cases, more explanation may be required, such as where there is coarse gold that has inherent sampling problems. Unusual commodities or mineralisation types (eg submarine nodules) may warrant disclosure of detailed information.

All sampling undertaken by Rainbow adheres to written procedures.

Grab/rock chip sampling: Individual REE veins are exposed over a strike length of at least 1 metre. Where possible, a structural measurement of dip and direction is recorded. Between 1kg and 3kg of outcropping/sub-outcropping material is collected per sample and transported in numbered bags to the Mutambu field office. The material is then broken into smaller chips with a geological pick and approximately 750g are put into cloth sacks, a sample ticket inserted and the sample number written on the bag with a permanent marker pen. Excess material is bagged in labelled sacks. All samples thus collected are transported to Rainbow's Bujumbura office where they are stored in a locked and secure room.

Channel sampling: Once a REE vein is exposed by pitting or trenching, the geologist delineates a sampling line on the outcrop. The channels, which are 10cm wide and 2-3cm deep, are then cut by hand using a chisel and hammer. A sample of the chipped-out material is collected every 1 metre channel length. Two to 4 kg of sample are collected and put in a pre-numbered calico bag and transferred to the Mutambu base camp. The sample size is reduced through a manual quartering protocol to produce a sample of 1kg.

Soil samples: soil samples were collected by rainbow during exploration in the past, however the results are not relevant to this Report.

Drilling techniques

Drill type (eg core, reverse circulation, open-hole hammer, rotary air blast, auger, Bangka, sonic, etc) and details (eg core diameter, triple or standard tube, depth of diamond tails, face-sampling bit or other type, whether core is oriented and if so, by what method, etc).

Diamond drilling

Cores were not orientated

HQ and NQ core sizes, depending on the hole depth and hardness of the lithologies encountered downhole. HQ size was mainly utilized in approximately the top 50m where the lithologies are highly fractured and with hardness ranging between soft and moderately hard. The NQ core size was utilized on drill holes that exceeded 50m depth and encountered more competent/hard rock. Standard core barrels were used in both core size.

Drill sample recovery

Method of recording and assessing core and chip sample recoveries and results assessed.

Measures taken to maximise sample recovery and ensure representative nature of the samples.

Whether a relationship exists between sample recovery and grade and whether sample bias may have occurred due to preferential loss/gain of fine/coarse material.

Core recovery was measured.

No relationship between sample recovery and grade is established.


Whether core and chip samples have been geologically and geotechnically logged to a level of detail to support appropriate Mineral Resource estimation, mining studies and metallurgical studies.

Whether logging is qualitative or quantitative in nature. Core (or costean, channel, etc) photography.

The total length and percentage of the relevant intersections logged.

Lithological logging (including radiometric detection using a handheld Polymaster).

RQD measurements made on the cores.

All cores were logged.

Logging at Kiyenzi is appropriate to support geological interpretation for 3D model creation.

Sub-sampling techniques and sample preparation

If core, whether cut or sawn and whether quarter, half or all core taken.

If non-core, whether riffled, tube sampled, rotary split, etc and whether sampled wet or dry.

For all sample types, the nature, quality and appropriateness of the sample preparation technique.

Quality control procedures adopted for all sub-sampling stages to maximise representativity of samples.

Measures taken to ensure that the sampling is representative of the in situ material collected, including for instance results for field duplicate/second-half sampling.

Whether sample sizes are appropriate to the grain size of the material being sampled.

Channel Samples: The channel samples selected for laboratory analyses were sub-sampled using a manual quartering method to achieve a weight of approximately 1,000g per sample.

Grab samples: samples weighing between 1kg and 3kg of material are collected and transported in numbered bags to the Mutambu field office. The material was then broken into smaller chips with a geological pick and approximately 750 g was filled into cloth sacks.

Core samples - half core cut with diamond saw. All sample submitted for analysis.

A sample ticket inserted and the sample number written on the bag with a permanent marker pen. These samples were sent for analysis at ALSC in Johannesburg. On request by Rainbow ALSC insert certified reference material ("CRM") and duplicates into the batch of 150 rock grab samples for REE ICP-MS and ICP-AES analyses. In total three AMIS185, three certified blanks and six duplicates (three inserted by Rainbow and three splits by ALSC) were inserted into the sample stream and were assigned specified sample numbers, using the sample number sequence of the field samples. In addition, ALSC inserted their own certified blank samples and duplicates as part of their internal quality assurance and quality control ("QAQC") process.

Analysis of duplicate samples has shown that sampling is representative of the in-situ material collect.

The vein material sampled is predominantly bastnaesite and monazite. The TREO grades have proved to be very consistent with low variability indicating that sample size is appropriate relative to the grain size of the material being sampled.

Quality of assay data and laboratory tests

The nature, quality and appropriateness of the assaying and laboratory procedures used and whether the technique is considered partial or total.

For geophysical tools, spectrometers, handheld XRF instruments, etc, the parameters used in determining the analysis including instrument make and model, reading times, calibrations factors applied and their derivation, etc.

Nature of quality control procedures adopted (eg standards, blanks, duplicates, external laboratory checks) and whether acceptable levels of accuracy (i.e. lack of bias) and precision have been established.

ALSC is an independent and accredited analytical facility in accordance with the recognised international standard ISO 17025:2005 for laboratory analysis, including the management requirements of ISO 9001:2008

Grab samples

Rainbow instructed ALSC to insert certified reference material ("CRM") and duplicates into the batch of 150 rock grab samples for REE ICP-MS and ICP-AES analyses. In total three AMIS185, three certified blanks and six duplicates (three inserted by Rainbow and three splits by ALSC) were inserted into the sample stream and were assigned specified sample numbers, using the sample number sequence of the field samples. In addition, ALSC inserted nine AMIS185, one SY-4, six certified blank samples and five duplicates as part of their internal quality assurance and quality control ("QAQC") process.

For major element analyses by XRF, ALSC inserted five NIST 694, five STSD-4, five certified blank samples and five duplicates as part of their internal QAQC procedure.

African Mineral Standards ("AMIS") in Johannesburg, South Africa, manufactures REE standard AMIS185 which was used as CRM. A total of three AMIS185 were randomly inserted into the batch of 150 samples. The results for all relevant rare earth elements were assessed and found to be within the accuracy limits specified by AMIS. The results for the nine AMIS185 standards inserted and analysed by ALSC, as part of their internal QAQC process, show acceptable accuracies for all relevant rare earth elements. ALSC inserted three OKA-2 and two TRLK certified standards as part of their internal QAQC procedure to monitor the accuracy of high Ce, La, Nd, Pr and Sm concentrations which were measured by ICP-AES analyses. The results for relevant rare earth elements show acceptable accuracies

The results for the three certified blank samples inserted by ALSC on behalf of Rainbow and the six blanks analysed as part of ALSC's routine QAQC procedure show no signs of contamination and the concentrations values for REE are within acceptable limits

Three field duplicates were randomly inserted by Rainbow and the sample batch. The results for all relevant REE were assessed and found to be within acceptable precision limits. The results for the three duplicate pairs created by ALSC on behalf of Rainbow and the five duplicate pairs inserted and analysed by ALSC, as part of their internal QAQC process, show acceptable precisions for relevant rare earth elements

Based on these results, it is concluded that the sampling and assay data are acceptable and sufficiently accurate.

Diamond Drilling Samples - ALS

The same laboratory procedures were used for the core samples as for the grab samples.

Rainbow's QAQC procedure consists of the insertion of one Certified Reference Material ("CRM"), one certified blank and one duplicate sample for every 50 samples submitted for analyses.

ALS utilises its own internal QAQC procedures which involve the insertion of CRM and blank samples as well as the analyses of duplicate samples for every batch.

For the Kiyenzi drill core samples, a total of 10 CRMs, 11 duplicates and 9 blank samples were inserted by Rainbow into the batches of samples that were dispatched to ALS for analysis. Control samples accounted for 5.6% of the Kiyenzi drill core samples submitted to ALS.

Based on the results, it is concluded that the sampling and assay data are acceptable and sufficiently accurate.

Diamond Drilling Samples - UIS

A second batch of 1,306 core samples (all from Kiyenzi) were submitted by Rainbow to UIS in 2019-20.

UIS Analytical Services is an   ISO/IEC 17025 accredited laboratory based in Pretoria (RSA).

The QAQC procedure for this batch of core samples was more stringent (than for the samples sent to ALS, see above) and consisted of the insertion of circa 1 CRM, 1 certified blank and 1 duplicate sample for every 30 samples.

As such 42 CRM's, 47 duplicate samples and 43 blank samples were inserted in the consignments to UIS, resulting in the QAQC samples accounting for 10% of the total samples analysed.

Furthermore, UIS utilised their own internal QAQC procedures which involve the insertion of CRM and blank samples as well as the analyses of duplicate samples for every batch.

Based on the results, it is concluded that the sampling and assay data for these core samples are acceptable and sufficiently accurate.

Verification of sampling and assaying

The verification of significant intersections by either independent or alternative company personnel.

The use of twinned holes.

Documentation of primary data, data entry procedures, data verification, data storage (physical and electronic) protocols.

Discuss any adjustment to assay data.

Verification activities were conducted by the Competent Person during the field visit and included:

1.     Inspection of selected observation and sampling points

2.     Review of sample sheets and recorded information

3.     Review of the project database for consistency, completeness and accuracy

4.     Review of sample submission and QA/QC protocol

5.     Review of QA/QC assay results

6.     Review project database against original Assay Certificates

7.     Inspection of the Kiyenzi cores and sample results

8.     Inspection of trenching and related channel sampling

9.     Inspection of REE vein exposures and the sampling thereof

10.  Rainbow follows an auditable chain of custody which ensured security and integrity of the results

Twinned holes have not been drilled.

All sampling data has been recorded in a DataShed database, hosted by CSA Global. Data entry validation procedures have been implemented.

Assay data has not been adjusted.

Location of data points

Accuracy and quality of surveys used to locate drill holes (collar and down-hole surveys), trenches, mine workings and other locations used in Mineral Resource estimation.

Specification of the grid system used.

Quality and adequacy of topographic control.

The position of all in-situ REE veins and float occurrences were recorded with a handheld GPS.

The accuracy of a handheld GPS is sufficiently accurate for the purpose of the grab sample results in identification of broad areas of REE mineralisation.

The position of most of the channel samples were surveyed with a cm-accuracy DGPS system.

The position of all drillhole collars were surveyed with the DGPS system.

Rainbow has also acquired high-resolution topographic data derived from drone-based surveys (2018-19); the 2 trial mines, Gasagwe and Murambi S, as well as key deposits, Kiyenzi, Gashirwe E and W, Gomvyi C, thus have cm-accurate topography data for the key deposits.

The Targets explored in 2019-20, i.e. Gakara, Rusutama, Bigugo and Gasenyi, were surveyed by a Burundi topographer using a Leica DGPS system with cm accuracy.

No downhole surveys were completed and the collar orientation was used down the entire length of the hole.

Rainbow used UTM Zone 35S (WGS84 Datum) for all field measurements which were subsequently converted into geographic system (Long and Lat).

The quality and accuracy of current topographic control is sufficient for the purposes of defining an Exploration Target

Data spacing and distribution

Data spacing for reporting of Exploration Results.

Whether the data spacing and distribution is sufficient to establish the degree of geological and grade continuity appropriate for the Mineral Resource and Ore Reserve estimation procedure(s) and classifications applied.

Whether sample compositing has been applied.

Grab samples:

Data points were located where fresh REE vein occurrences were present. The spacing does not follow a systematic grid and is dependent on the observed outcrop of REE veins.

Soil samples:

Collected at 25 m intervals along 500 m long lines which were spaced at 50 m apart. The soil sampling survey was not considered useful in identifying REE mineralisation, even though alternate tighter grid intervals were trialled.

Channel samples:

Undertaken mainly at Gasagwe, Murambi South, Gashirwe West, Gomvyi Centre, Kiyenzi

Samples were taken at 1 or 2 m intervals. However only a selected number were submitted for assaying by ALSC, as the grade of the bastnaesite and monazite veins was very consistent. Identification of the location, width and geometry of veins is critical for generation of a geological model.

The channel sample data at Gasagwe, Murambi South and Gomvyi Centre are suitable for the purposes of defining an Exploration Target.

Drill core samples:

The Kiyenzi drill holes are located on a variable grid of between 15 and 33 m.

Samples were not composited.

Half cores were collected to sample distinct lithological units, with a sample length never exceeding 1 metre.

Where brecciated units, believed to be highly mineralised, were logged, such intersections were carefully and separately sampled, even if they were only centimetres wide.

Diamond drilling at Kiyenzi is sufficient to construct a 3D geology and grade model.

Orientation of data in relation to geological structure

Whether the orientation of sampling achieves unbiased sampling of possible structures and the extent to which this is known, considering the deposit type.

If the relationship between the drilling orientation and the orientation of key mineralised structures is considered to have introduced a sampling bias, this should be assessed and reported if material.

Grab samples were taken where REE veins were exposed on the surface

The grab sampling procedure ensured maximum extraction of clean vein material. Vein thickness, continuity and strike and dip measurements were recorded where possible.

The channel sampling was completed based on 2 different requirements:

1.     To obtain adequate "bulk" sample of vein material, by constructing the channel along the strike of the vein and carefully collecting all visually obvious bastnaesite or monzonite rich vein material - ignoring all visual "waste" material.

2.     Regular cross sections through the vein material, with the channel constructed to sample visual "waste" and visual selvedge either side of the observed vein. This was an attempt to understand the extent of REE mineralisation at the edges of the visual vein material and to determine if REE mineralisation is present, but not visible at naked eye, in the host rock between REE veins

Diamond drilling at Kiyenzi was completed using multiple orientations. The understanding of the orientation of mineralisation at Kiyenzi is insufficient to establish the relationship between drilling directions and mineralisation trends.

Sample security

The measures taken to ensure sample security.

Standard operating procedures ("SOP") were used for the handling and transportation of samples to ensure a secure and auditable chain-of-custody from the field to the laboratory. Local sample transport was exclusively handled by Rainbow staff. Local courier companies, Brucargo or DHL, were responsible for shipment to ALS (SA and Canada) and SGS SA (sample for metallurgical test work).

All analysed sample data has been verified and security maintained by loading into a Datashed database hosted by CSA Global.

Audits or reviews

The results of any audits or reviews of sampling techniques and data.

Sample collection, submission, QA/QC protocol and assay database were reviewed by the Competent Person and were determined to be appropriate for estimation of an Exploration Target.

Section 2: Reporting of Exploration Results

JORC Code explanation


Mineral tenement and land tenure status

Type, reference name/number, location and ownership including agreements or material issues with third parties such as joint ventures, partnerships, overriding royalties, native title interests, historical sites, wilderness or national park and environmental settings.

The security of the tenure held at the time of reporting along with any known impediments to obtaining a licence to operate in the area.

A 'Permis d'Exploitation' (Mining Licence) was lodged by RIR on 10 November 2014 and granted by the Burundi Ministries of Energy and Mining and Finance and Economic Development on 27 March 2015 and ratified by Presidential Decree No. 100/110 on 18 April 2015. The ML is valid for 25 years with 10 year renewal increments available.

A further Decree, No. 100/194, was signed on 16 June 2015 stipulating that the State of Burundi has a 10 % interest in Rainbow Mining Burundi; the balance, 90%, being held by the parent company, RIR.

Rainbow does not own the surface rights covered by the ML but has free and unrestricted access to the entire Project area, following consultation with the local communities.

Rainbow submitted Environmental and Social Impact Studies to the Ministry of Environmental Affairs and obtained compliance certificates (No. 007/2015) on 30 March 2015 (No. 010/2015) for the ML.

Exploration done by other parties

Acknowledgment and appraisal of exploration by other parties.


In 1936, SOMUKI discovered bastnaesite in alluvial deposits in the Gakara area, which was confirmed by analysis at laboratories in Entebbe (Uganda), Liverpool (England) and Leuven (Belgium).

From 1941 to 1942, research into the bastnaesite occurrences continued and the first mining tests were undertaken. Approximately 14 tonnes of bastnaesite material were produced from in-situ veins at Gakara.

The increase in REE prices from 1947 to 1957 resulted in renewed mining activities at the Gakara and Rusutama deposits from 1948 onwards. In total, 2,137.3 tonnes of bastnaesite was reported to have been produced from these two deposits - SOBUMINES and BGR reports.

Thoreau et al. (1958) published an article on the Karonge deposit (Gakara) detailing results of a geological survey of the deposit. Initially they postulated that the REE mineralisation was only associated with the quartzites, until the excavation of the Rusutama quarry near Gakara, along strike from the Gakara mineralisation revealed that REE vein mineralisation at Rusutama occurs in gneiss and schists.

A further two discoveries of bastnaesite mineralisation were made at Gasenyi and Murambi, in a different geological context to the initial discovery. The bastnaesite mineralisation occurs in a network of veins and stockworks (5 cm to 15 cm thick) associated with pegmatites. The mineral paragenesis is: bastnaesite, quartz, barite and sulphides (pyrite and galena).

In the late 1950s, genetic similarities between the REE mineralisation at Gakara and Mountain Pass, California, were recognised, although the absence of carbonatites at Gakara and the generally more complex mineral assemblage at Mountain Pass were noted.

Exploration and mining stopped in 1957, with a fall in the global REE prices.


Sobumines returned to the Gakara area in 1965, by which time the general understanding of the geochemistry, mineralogy and metallurgical characteristics of REE had advanced.

From 1966 to 1969, mining of the Gakara and Rusutama deposits intensified. In 1968, exploration work and geological mapping was undertaken at Gasenyi and several other known REE occurrences. Various types of mineralisation were noted, identifying the need for detailed studies to facilitate the treatment and purification of the material to produce the required concentrate.

Aderca and Tassel undertook detailed studies of the Gakara deposit in 1971. Their work focussed on various aspects of REE mineralisation, and mineral types and associations, from samples obtained from various operational pits.

From 1972 to 1978, research was conducted by several Sobumines geologists and engineers. More than 30 REE occurrences were investigated as part of their exploration campaign for bastnaesite.

Exploration and mining operations were extended to the other sites including Gasenyi, Murambi, Gasagwe and Mugere. Mining operations until 1978 comprised open pits and occasional galleries for most deposits.

In 1978 Sobumines stopped all operations due to a fall in global REE prices which rendered mining in the Gakara area uneconomical.


From 1981-1985 Germany Bundesanstalt für Geowissenschaften und Rohstoffe ("BGR"), undertook an exploration and evaluation programme on six selected REE-bearing sites, within a framework of bilateral cooperation with the Burundi Government. An estimated 5,000 tonnes of REE material at a grade of 50% TREO was postulated for the six sites. The Gasagwe deposit alone was estimated by BGR to contain approximately 2,800 tonnes.

In 1985, the BGR undertook metallurgical test work on the Gakara REE mineralisation as part of their planning to resume small-scale mining at the Gakara deposit and to comply with REE concentrate specifications as required by the international market in the mid 1980's. The BGR study concluded that the tested bastnaesite/monazite mineralisation could be upgraded on site to a marketable product.


Deposit type, geological setting and style of mineralisation.

The Project area is situated within the northeast-trending Kibaran Fold Belt ("KB") which stretches across Burundi from the eastern Democratic Republic of Congo ("DRC") to western Tanzania. The KB in Burundi consists of a highly deformed sequence of Mesoproterozoic granites, granitoids and amphibolite-greenschist facies metasedimentary and metavolcanic rocks, referred to as the Burundi Supergroup.

The geology and tectonic framework of Burundi and neighbouring countries have been strongly influenced by repeated episodes of rifting along existing structural trends. This resulted in the emplacement of numerous carbonatites and alkaline complexes, spanning a broad range in age from Late Proterozoic to Cenozoic.

The Property geology is dominated by the Mugere granitoids which contain numerous inclusions of metasedimentary rocks such as the Karinzi and Makara "fragments" which are commonly fault bounded at the contacts with the granitoids. These granitoids are the dominant host rocks for the bastnaesite/monazite mineralisation in the Project area.

REE mineralisation is hosted within a network of bastnaesite/monazite-bearing veins and veinlets which range in thickness from a few centimetres to a few tens of centimetres. The veins exhibit variable orientations and attitudes, although there appears to be a broad correlation with regional structures and dominant trends.

The REE mineralisation at Kiyenzi is thought to be within a breccia pipe. The interpretation of the detailed geology is ongoing.

Drill hole Information

A summary of all information material to the understanding of the exploration results including a tabulation of the following information for all Material drill holes:

11.    easting and northing of the drill hole collar

12.    elevation or RL (Reduced Level - elevation above sea level in metres) of the drill hole collar

13.    dip and azimuth of the hole

14.    down hole length and interception depth

15.    hole length.

If the exclusion of this information is justified on the basis that the information is not Material and this exclusion does not detract from the understanding of the report, the Competent Person should clearly explain why this is the case.

The Kiyenzi drillhole collar information and REE intercept grades and intervals are presented in the full technical report available on the Company's website at: http://rainbowrareearths.com/investors/corporate-documents/

Data aggregation methods

In reporting Exploration Results, weighting averaging techniques, maximum and/or minimum grade truncations (eg cutting of high grades) and cut-off grades are usually Material and should be stated.

Where aggregate intercepts incorporate short lengths of high grade results and longer lengths of low grade results, the procedure used for such aggregation should be stated and some typical examples of such aggregations should be shown in detail.

The assumptions used for any reporting of metal equivalent values should be clearly stated.

Exploration results are reported in the form of an Exploration Target.

The Exploration Target ("ET") is subdivided into Vein Hosted or Breccia Hosted REE mineralisation.

For the Vein Hosted REE the ET was based on 3D modelling of the zone of potential mineralisation defined by either historical mining, current trial mining, exploration bulk sampling or exploration grab and/or trench samples. The tonnage of potential mineralisation was extrapolated based on a range of waste:ore strip ratios estimated from the historical and RMB trial mining data. The grade range was estimated from the current pilot plant trial mining feed grade.

For the Breccia Hosted REE at Kiyenzi the ET was based on a 3D model using the 2018 diamond drilling data to define a grade tonnage distribution. This distribution was extrapolated to include areas at depth where the breccia pipe is expected to be mineralised and laterally to an area of mineralisation defined by exploration sampling.

No aggregation of assays was used for the Vein Hosted ET

The Kiyenzi drilling was composited to 1m downhole lengths for use in the grade tonnage model.

No metal equivalent value was used.

Relationship between mineralisation widths and intercept lengths

These relationships are particularly important in the reporting of Exploration Results.

If the geometry of the mineralisation with respect to the drill hole angle is known, its nature should be reported.

If it is not known and only the down hole lengths are reported, there should be a clear statement to this effect (eg 'down hole length, true width not known').

The relationship between Breccia Hosted mineralisation at Kiyenzi and the orientation of drillhole samples is not yet clearly understood. The mineralisation is assumed to be contained within a breccia pipe created by exhalative extrusion from a carbonatite source.

The relationship between down hole mineralisation intercepts and true mineralisation width is not known.


Appropriate maps and sections (with scales) and tabulations of intercepts should be included for any significant discovery being reported. These should include, but not be limited to a plan view of drill hole collar locations and appropriate sectional views.

Please refer to the full technical report available on the Company's website at: http://rainbowrareearths.com/investors/corporate-documents/

Balanced reporting

Where comprehensive reporting of all Exploration Results is not practicable, representative reporting of both low and high grades and/or widths should be practiced to avoid misleading reporting of Exploration Results.

Please refer to the full technical report available on the Company's website at: http://rainbowrareearths.com/investors/corporate-documents/

Other substantive exploration data

Other exploration data, if meaningful and material, should be reported including (but not limited to): geological observations; geophysical survey results; geochemical survey results; bulk samples - size and method of treatment; metallurgical test results; bulk density, groundwater, geotechnical and rock characteristics; potential deleterious or contaminating substances.

Further development of exploration knowledge and REE target generation was completed by TECT Geological Consultants. Refer to the Technical Report for details on the work completed by TECT.


Further work

The nature and scale of planned further work (eg tests for lateral extensions or depth extensions or large-scale step-out drilling).

Diagrams clearly highlighting the areas of possible extensions, including the main geological interpretations and future drilling areas, provided this information is not commercially sensitive.

Evaluation of the REE occurrences through surface exploration mapping and sampling is ongoing, work includes:

1.     Cleaning and sampling of additional historical mining open pits.

2.     Follow-up on new REE targets identified by the TECT geological study.

3.     16,200 m of diamond core drilling to convert the 9 defined vein hosted Exploration Targets to a Mineral Resource during the next 15 months.

4.     Continue trial mining and production of concentrate with the pilot plant to assist with defining a Mineral Resource

Diagrams of the Exploration Targets are presented in the Technical Report.


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