Geographic Minerals

Kadyrelite: Properties and Occurrences

Kadyrelite: Properties and Occurrences

Kadyrelite is a mineral with the chemical formula Hg4(Br, Cl)2O discovered in 1987. Although the mineral is white, the black refers to its reaction with ammonia, which gives a beautiful black coloration. It was named for the locality: Kadyrel deposit, Tuva, Siberia, Russia.

General Information

  • Formula: Hg4(Br, Cl)2O
  • Crystal System: Isometric
  • Name: For the Kadyrel deposit, Russia, where it occurs.
  • Type: Isotropic

Fig: Kadyrelite


This mineral has an adamantine-resinous luster, with the pale yellowish-white streak. The fracture on this mineral is sectile, meaning curved shavings or scrapings produced by a knife blade.

  • Cleavage: None
  • Color: Orange, Dull orange.
  • Diaphaneity: Transparent
  • Fracture: Brittle – Generally displayed by glasses and most non-metallic minerals.
  • Habit: Granular – Generally occurs as anhedral to subhedral crystals in matrix.
  • Hardness: 2.5-3 – Finger Nail-Calcite
  • Luster: Vitreous – Adamantine
  • Streak: Yellow-orange.

Occurrence: In cavities in carbonate veins in a mercury deposit. It occurs in an uncommon secondary mineral, formed through the alteration of other mercury minerals.

Association: Eglestonite, calomel, kuzminite, corderoite, lavrentievite.