FIRST FLOOE. 
63 
including most of the stony minerals, begins with Cuprite (10a), General 
an important ore of copper (copper 89, oxygen 11). M^erals^ 
Spinel (lOe), in its transparent varieties, is one of the pre- 
cious stones : the deep red is the Spinel Euby (less dense and 
less hard than the true ruby), the rose-tinted is the Balas Euby, 
and the yellow or orange-red is the Eubicelle of the jewellers : 
sometimes, too, it has a dark blue colour. On account of their 
hardness the less valuable specimens are used for the jewelling 
of watches. 
Magnetite, or Magnetic iron ore (lOf), is the richest and most 
valuable of the ores of iron, of which metal it contains 72 per 
cent. It is the natural loadstone. 
Chrysoberyl (9e) is another of the precious stones. The beauti- 
ful greenish-yellow variety, almost equal in lustre and hard- 
ness to the sapphire, is the Oriental Chrysolite of the jewellers ; 
another variety, with a peculiar play of light, is the true Cat's- 
eye; while a third, green by sunlight but red by candle- or 
lamp-light, is the stone knoAvn as Alexandrite. 
Corundum (9h), when clear and of the proper colour, is, after 
the diamond, the most precious of stones. When pure it is the 
colourless variety known to jewellers as the Lux-sapphire : but 
with very minute traces of colouring ingredient it assumes the 
richest and most varied hues ; when red it is the true Euby; when 
azure it is the Sapphire ; while the yellow, green, and purple 
varieties are known respectively to jewellers as the Oriental 
Topaz, Emerald, and Amethyst ; the prefix oriental," though 
at first used to suggest that the stones are not the ordinary topaz, 
emerald, and amethyst, but others of a similar colour coming 
from the East (India, Ceylon, Siam, Pegu, &c.), was afterwards 
understood to imply only the excellence of their characters. The 
Star-stones, another variety of corundum, when placed in a 
strong light show a six-rayed star. 
Hsematite (11a) is a valuable ore of iron. 
Cassiterite, or tin-stone (llf), is the ore of tin, of which metal 
it contains 79 per cent. 
Zircon (13b), when clear and without flaws, is one of the 
precious stones : one variety with peculiar red tints is the 
Hyacinth or J acynth, while the colourless, yellowish, and dull 
green are termed Jargoon : the colourless variety, owing to its 
