Orpiment is a rare
mineral that usually forms with realgar. In fact the two minerals are
almost always together. Crystals of orpiment are extremely rare as it
usually forms masses and crusts. The masses are sometimes transparent to
a degree and have a gemmy quality to them. The yellow color is special
to orpiment and can be confused only with a few other minerals. Orpiment
is derived from the latin auripigmentum, or golden pigment. Its use as a
dye or pigment is limited due to its instability. Over time, orpiment
will deteriorate into a powder. The process takes a long time, but
exposure to light will accelerate it. Specimens should be stored in
dark, enclosed containers.
Nenhum comentário:
Postar um comentário