Diamonds found in French Guiana

Toronto-listed Guyanor Ressources has discovered diamonds in a metamorphosed ultramafic rock within its Dachine permit area in French Guiana.

Guyanor, which is 70% owned by Golden Star Resources (TSE), has traced the rock, which it believes to be kimberlite, through 3.5 km of length and 0.5 km of width.

Guyanor and BHP Minerals agreed in December to explore jointly the Dachine permit area for the source of a secondary diamond occurrence identified in the 1970s. To date, six outcrops have been sampled, all of which have yielded microdiamonds. As well, samples from 11 shallow auger holes bored on the main ultramafic body have yielded microdiamonds, and recent results from a deeper hole (152 metres) revealed at least 2,658 microdiamonds in a 34.5-kg sample covering a length of 25 metres. A second, shallower hole, drilled on what is thought to be a younger, smaller ultramafic body, yielded little.

Results from three additional drill holes, which intersected the main body, are pending.

Processing of 1.8 tonnes of saprolite from auger holes yielded 8 macrodiamonds (greater than 1 mm), the largest being 2.4 mm in diameter. The recovered stones are off-white to grey or brown in color, and most contain inclusions. The microdiamonds recovered, by comparison, are dominantly brown in color, clear, and consist mainly of fragments, fragmented dodecahedrons and more complex crystal forms.

Four distinct populations of microdiamonds have been identified, the most important of which consists of clear, white microdiamonds; of these, the best stone found was a 0.6-mm, clear, white, perfect octahedron.

Based on these encouraging results, and contingent upon continued success, BHP (the operator) and Guyanor are contemplating a small bulk-sampling program, to be carried out in the second or third quarter.

Below are the results of sampling at the Dachine project:

Weathered bedrock samples

SampleWeightMicro-

(kg)diamonds

DR-018513

Outcrop B46.91

Outcrop C46.918

Outcrop D38.642

Outcrop E40.254

DACH-0476.323

Auger samples

DACT-01391036

DACT-0238645

DACT-0342.24

DACT-0440492

DACT-0544.240

DACT-0636.43

DACT-0734.7141

DACT-1118.4890

DACT-1218.613

DACT-1320.25

DACT-1418317

DACT-1521.10

Core samples, Hole DDAC-04

EE8.6 – 18.3 m12.50

E29.1 – 41.9 m2918

E79.6 – 105.1 m292

110.1 -137.8 m31.60

Core samples, Hole DDAC-05

10 – 26.4 m10.8169

E26.4 – 41.9 m20.96

E41.9 – 78.6 m48.7pending

E78.6 – 96.9 m22.3146

E96.9 – 126.8 m37.7486

126.8 -151.8 m34.52658