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Pink Pearls.
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hematite
is said to be found, and to be worked up so as to represent black
Pearls. Such imitations, however, do not in the least mislead a
practised eye, for they lack the true sheen and lustre of a natural
Pearl, and are immediately distinguished by their weight, the density
of hematite being considerably greater than that of carbonate of
lime—the substance of the Pearl.
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Pink Pearls. It
has sometimes been assumed that the ancients were familiar with pink
Pearls—the assumption being based on the slender evidence of a passage
in Pliny, which refers to Pearls of a ruddy hue. In Dr. Holland's
quaint translation we read that " Pearles were wont to be found in our
seas of Italie ; but they were small and ruddie, in certain little
shell-fishes which they called Myae."
The
origin of the pink colour is as obscure as that of the black referred
to in the previous section of this chapter. Chemists are aware that
carbonate of lime assumes a pink tint by the presence of manganese,
and a red colour by that of oxide of iron but it seems more likely that
the delicate roseate hues of the pink Pearl are referable to some
subtle organic pigment.
Pink Pearls are found in the rivers of South
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