Man first discovered lapis lazuli almost 7,000
years ago. It has been found in ancient civilizations such as Egypt, Persia,
Greece, Rome and the Middle East.
It’s an easy, workable stone, so it’s not used
only in jewelry, but also carving, mosaics, ornaments. It is also processed to
make blue pigments for make-up and painting.
In Egyptian culture, this stone has an
important connection with religion. Archaeologists found abundant amulets and
talismans made in Lapis.
Its vivid blue color made it an important
component of some European masterpieces. The frescos of some important medieval
churches in Italy were made using the blue pigment made from lapis lazuli. It is pretty impressive if you consider that
at that time the Lapis was really expensive and was available only from one far
source: Afghanistan.
Lapis lazuli is not a gem, but a rock, which
means that it is an aggregate of several minerals, including but not limited to:
Lazurite, Calcite and Pyrite. The quality of the stone is determined by the percentage
of these three minerals. For example, if the calcite matrix is too present in
the stone, it looks white and therefore less appealing.
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| Lazurite |
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| pyrite |
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| calcite |
The presence of the pyrite flakes makes the
stone look like a sky full stars, and this is the reason why people believed
that the stone unleashed peace and relieved
stress. Kings and queens used it in the past as a powerful status symbol; it
was considered a piece of heaven given to men by the gods.
The top quality color is a violetish blue with
no-visible calcite and some gold looking pyrite flecks. The presence of an
excess of calcite or pyrite can lower the quality of the stone and make it look
greenish and less valuable. Its hardness is 5 to 6 on the Mohs scale.
It can be found in different shades of blue,
depending on the other minerals in the aggregate.
On Earth, there are not many Lapis mines: the
finest quality is found in Afghanistan, the oldest source, but it is found also
in Chile and Russia.
Because
fine-quality Lapis stones are highly priced, treatments are common, but not
stable, which makes the treated stone less valuable than untreated one. The
dyeing treatment is used frequently; it’s used to enhance the blue coloration and
cover the white coloration caused by the calcite but can be rubbed away with
acetone. Usually after dyeing, it is also impregnated with wax to protect the
stone and make it appear shiny.
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| Gilson |
Lapis
imitations are plenty and are old as lapis itself. Glass, plastic and ceramic
are very common in the market, they are manmade at a low cost. Another manmade material created just to
imitate Lapis is the Gilson Imitation Lapis Lazuli, which apparently looks just
like the original, but is actually very porous. Is Its hardness is 3 on
the Mohs scale and the luster is dull. The color is perfectly even and the
pyrite flakes appear like sprinkles on the surface. Other substitutes are
Chalcedony and sodalite.
Until the
1950s it was one of the December birthstones, so it can be used as a good alternative
to Tanzanite and Turquoise for people who were born in that month.
