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Pyrite
Pyrite was and still is employed as an ornamental
material on account of its luster, its elegant crystal form,
the ap pearance of some roughly radial concretions or certair
groups of crystals, and the fact that it can be cut and polished.
It is often confused with the dimorph marcasiteanother, very
similar mineral of the same color which is much less common
and has orthorhombic symmetry. Ir fact the misnomer is now
so widespread that it is nearly always referred to as marcasite
when used for ornamentai purposes, even if the obvious cubic
crystal form leaves nc doubt as to its being pyrite. If anything,
it is the concreteo nodules of sedimentary origin that could
occasionally be marcasite.
Appearance Isolated cubes with striated faces,
pentagonal dodecahedra, or small groups of these two forms
with their natural facets are normally used, although sometimes
the nodules are used instead. These consist of minute crystals
with a flattened, radial structure, a minutely granular surface
and the characteristic, metallic yellow color Small stones
(2 to 3 millimeters in diameter) have sometimes been given
a flattened circular, rose cut with only three polished facets
on top.
They are generally set in white metal, for
obvious reasons of contrast, and are sometimes merely glued,
rather than set, onto their supports They are often found
on necklace clasps and old-fashioned, inexpensive brooches.
Distinctive features In uncut stones, the shape of the crystal
combined with the color, luster, and high density, or the
form of the nodules, are unmistakable. Even when cut its appearance
is unique.
Occurrence It is very common
and widely distributed throughout the world, even in the qualities
suitable for ornamental purposes.
Value Extremely low.
Simulants and synthetics Because of its widespread
occurrence, it is neither imitated nor produced synthetically.
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