Orpiment



 

Orpiment, refractive indices of a=2.4, b=2.81, g=3.02.

Orpiment is an orange to yellow mineral that is found worldwide, and occurs as a sublimation product in pigment) because of its deep yellow color.

Orpiment is also known as "King's Yellow", "Chinese Yellow" and "Yellow Orpiment"[1] .

Historical uses

It was an important item of trade in the Roman Empire and was used as a medicine in China although it is highly toxic. It was also used as a fly poison and to poison arrows. Because of its striking colour, it was also a favourite with alchemists searching for a way to make gold, both in China and the West.

Orpiment was ground, processed and used for centuries as a dye-based colors of the 19th century.

Contemporary uses

It is presently used in the production of infrared-transmitting glass, oil cloth, linoleum; in semiconductors and photoconductors, as a pigment and in fireworks. Mixed with two parts of slaked lime, orpiment is still very commonly used in rural India as a depilatory. It is also used in the tanning industry to remove hair from hides.

Crystal structure

Image gallery

References

  • The Merck Index: An Encyclopedia of Chemicals, Drugs, and Biologicals. 11th Edition. Ed. Susan Budavari. Merck & Co., Inc., N.J., U.S.A. 1989.
  • William Mesny. Mesny’s Chinese Miscellany. A Text Book of Notes on China and the Chinese. Shanghai. Vol. III, (1899), p. 251; Vol. IV, (1905), pp.26.
 
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