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Turquoise is not a primary element like
iron, copper, silver, etc. Rather, it
is a secondary element formed over time as a
result of minerals that accumulate in
the planet's crust through two processes, weathering and
oxidation.
Turquoise usually
occurs as encrustation in cracks or as
nuggets.
As water moves through porous rock, minerals
are dissolved, such as copper, aluminum and
iron. Often these minerals come from
other secondary elements; copper might come
from azurite, for example.
Over eons of time, these minerals accumulate
in pores, cracks and crevices to form
deposits of the material we know as
"turquoise." Oxidation of other
minerals present at the site contribute to turquoise
formation.
The color of the stone can vary depending on
the amount of iron and other minerals
present. Since turquoise forms in
other rocks, it often veined with other
minerals to create a beautiful matrix.
Most turquoise forms in drier climate, and
often in rock formations that originated
from volcanic activity; such formations are
conducive to turquoise because they have
high levels of iron oxides.
The process of formation can differ from
region to region, and even from different
locations in the same region, leading to
unique turquoise appearances. For this
reason, turquoise is often named after the
mine from which it came. An example is
"Sleeping Beauty Turquoise," which comes
from the sleeping beauty mine near Globe,
Arizona. |
