Enstatite - rich Ureilite, polymict, very diamond-rich

a heavily shocked ureilite

Dar al Gani 1023


Found August 19th 1999 , Dar Al Gani plateau Al Juffra.

A stone of 149 g was found by an anonymous collector in the Dar al

Gani desert. Mineralogy and classification (H. Takeda, Chiba; T.

Ishii and M. Ohtsuki, UTok): fragmental breccia, with lithic and

mineral clasts embedded in a cataclastic matrix of predominantly

ureilitic material. The pyroxene

composition ranges from En79Wo6 to En62Wo4 and En59Wo31; olivine

composition ranges from Fo90 to Fo75.

The plagioclase composition

ranges from An13Ab85 to An33Ab62.

DaG 1023 is one of the most heavily shocked ureilites known.

All mafic silicates are converted into very fine grained materials with a granoblastic texture;

carbonaceous vein materials are lost from many grain boundaries;

glassy shock-vein materials are observed at some parts of the thin

section. Olivine (80 vol. %) is more abundant than pyroxene (20 %).

Pyroxene composition ranges from En86Wo2 to En77Wo10 and En69Wo6;

olivine composition ranges from Fo96 to Fo66. The stone appears weathered,

with a brownish colour in hand specimen, but in thin section the

weathering grade appears to be very low.