Pararealgar is the alteration
product of the mineral Realgar
. It forms when Realgar is exposed to light, which causes a physical change in the structure of the mineral and transforms it into a new mineral. Pararealgar is has the same chemical composition
and chemical formula
as Realgar, but its crystal form differs. Pararealgar is also different in color than Realgar; whereas Realgar is bright red, Pararealgar is bright orange or yellow, and additionally has a more powdery consistency.
Pararealgar is usually associated with Realgar, and specimens can be partially altered
. It is not uncommon for specimens to be only partially altered in sections, creating yellow and red color zones. Once a significant alteration has taken place, the mineral will start to crumble. The
mineral that Realgar transformed into was generally
assumed to be Orpiment
, but recent scientific analysis has in fact
determined the orange alteration product as Pararealgar. Pararealgar, like Realgar, is photosensitive, and will become
and eventually crumble into a yellow powder if left in the
light. Specimens should be stored enclosed and covered
to prevent their exposure to light.
Pararealgar contains a significant amount of poisonous arsenic, and is
itself somewhat toxic. Washing hands is recommended after handling specimens, especially if they are powdery.