beautiful stone, exceeding in brilliancy and fire the finest
emeralds. There are several of splendid green tint in the
Museum of Natural History, in Paris, but the best known
specimen is in Dresden, which Mr. Hamlin considers as " one
of the five paragons among all the gems of the world."
It has been stated that one of the finest green diamonds
yet discovered is owned by an American amateur of precious
stones.
Black diamonds are, probably, as rare, or nearly so, as the
red shades of this gem. A coal black specimen weighing
three hundred and fifty carats, exhibited at the London Exposition of 1851, excited the surprise and admiration of all connoisseurs, on account of its color and size. Those of a brown
color, and a variety presenting a cloudy or milky appearance
resembling the opal, are sometimes met with.
A fine collection of colored diamonds, gathered by the untiring patience of a Tyrolese, who devoted the greater part of
his life in searching for specimens, are seen in the Museum of
Vienna. A spray, composed of colored diamonds of all the
tints that could be collected in ten years' research, constituted,
says Mr. King, the most charming piece of jewelry he ever
beheld. The Townshend gems include a great variety of
colored diamonds — black, yellow, green, gray, indigo, cinnamon, and others.
Frangibility. — The opinion was formerly entertained that
the diamond was infrangible, and could not be broken even by
a blow of the hammer, a mistake arising, doubtless, from making hardness synonymous with toughness. The fact is that the
hardest of gems is one of the most brittle, and has been broken
by simply letting it fall upon the floor. It can be split with a
knife in the direction of its cleavage planes, or pulverized in a
mortar. Many valuable specimens have been needlessly sacri-
