Considering the particular emerald which is a variety of beryl -although the name emerald in the trade is applied somewhat loosely to any stone which is of the same colour, or approaching the colour of the beryl variety -this emerald only differs chemically from the beryl, just described, in possessing an addition of oxide of [...]
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By cleavage is meant the manner in which minerals separate or split off with regularity. The difference between a break or fracture and a “cleave,” is that the former may be anywhere throughout the substance of the broken body, with an extremely remote chance of another fracture being identical in form, whereas in the [...] |
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