0.9" Realgar Crystals on Quartz - Peru

Realgar is an arsenic sulfide mineral with the chemical formula of AsS. Realgar is known for its lustrous red hue, with the most pristine specimens being transparent with sharp crystals. The crystal structure is typically stubby and prismatic, with botryoidal and earthy clumps known to be possible formations as well.

Following prolonged/repeated periods of time under light, realgar will alter to pararealgar. If further left exposed, the pararealgar will crumble to a yellow dust. This mineral instability has especially been experienced in museums where consistent light exposure has caused specimens to crumble over time. However, periodic exposure to light shouldn't alter realgar specimens.

Realgar contains a significant amount of poisonous arsenic, making it somewhat toxic. Therefore, washing hands following handling of realgar specimens, is recommended.