172 
NON-METALLIC MINERALS. 
Case AT. 
The compounds of Silica or silicic acid, with various bases, foim a \ ery 
long and most diversified series of minerals. The collection commences 
with those kinds which from their hardness and colour (in selected 
specimens) have been termed gems or precious stones. With theA are 
placed a few species not strictly admissible in the same chemical group, 
but allied to the others either by their occurrence in nature or by 
their physical characters. The applications of most of this series are 
directly illustrated by the specimens. 
Anhydrous Silicates. 
889. Beryl ( Silicate of Alu¬ 
mina and Glucina). in coarse- 
a'rained Glranite. 
United States, 
890. Beryl, in Gneiss. 
United States. 
891 and 892. Beryl, crystals 
embedded in Quartz. 
United States. 
893. Beryl, fragment of a large 
crystal. 
United States. 
894 and 895. Beryl, in opaque 
blue crystals embedded in Quartz. 
Gweebarra Range, Co. Donegal, 
Ireland. 
896. Beryl, detached crvstal. 
Gweebarra Mts. 
897. Beryl, opaque white crys¬ 
tals in Granite. 
Killiney, near Dublin, 
898. Beryl, with crystallized 
Tinstone. 
Brittany. 
899. Beryl, brownish-yellow 
transparent crystal. 
Siberia. 
900. Beryl, transparent, green. 
Invercaidd, Aberdeenshire. 
901. Beryl, green crystal. 
Australia. 
902. Beryl, green transparent 
crystal, with black Quartz. 
Siberia. 
903. Beryl, large green trans¬ 
parent crystal approaching aqua¬ 
marine. 
Siberia or Brazil. 
904. Aquamarine, or Precious 
Beryl. 
Odontschelon, Siberia. 
905 to 907. Aquamarines, cut. 
908. Emerald, with Calcite 
. and Iron Pyrites, in a vein pene¬ 
trating black Limestone. 
Muzo, New Granada. 
909. Fossils, apparently Am¬ 
monites of the Cretaceous jieriod, 
from the same locality as the last 
specimen. 
Nos. 908 and 909 presented by Sir 
William Hooker. 
910 to 911. Emerald, crvstal- 
* i/ 
lized, in matrix. 
Muzo. 
\ 
912. E3IERALD, in Calcite. 
Muzo. 
913. Emerald, crystal in gra¬ 
nite, with felspar and smoky 
quartz. 
Mourne Mountains. 
914 to 918. Emerald, crystal¬ 
lized. 
919. Emerald, cut as brilliant. 
Mourne Mountains. 
920. Emerald, cuten cabochon. 
921. Intaglio in Emerald, of 
the cinque-cento period. Female 
portrait. 
From the Hertz Collection. 
922. Dioptase {Hydrous Sili¬ 
cate of Copper). 
Altyn-Tubeh, Kirghese Steppes, 
Siberia. 
This specimen ssas sold in London by 
a dealer in precious stones as Emerald! 
923. Parisite {^Carbonate of 
Cerium, Lanthanum, and Didy- 
mium, loith Fluoride of Calcium ; 
Bunsen). 
From the Emerald Mines of Muzo, 
New Granada. 
Presented by C. Michelsen. 
