Mineral Information and Data:

CaZnAsO4(OH) [CNMNC approved formula]

Named to honor Professor Austin Flint Rogers (1877-1957), American mineralogist, Stanford University, Palo Alto, California, USA.

IMA status : Valid species (Pre-IMA 1935) Grandfathered
(8th edition) :  
  (41) Anhydrous Phosphates Containing Hydroxyl or Halogen
  (41.05) where (A B)2 (XO4) Zq
  (41.05.01) Adelite Group
(10th edition) :
  (08) Phosphates, Arsenates, Vanadates
  (08.B) Phosphates, etc. with Additional Anions, without H2O
  (08.BH) With medium-sized and large cations, (OH,etc.):RO4 = 1:1
Crystal system: Orthorhombic System
Point group (H-M): 222 — disphenoidal
Unit cell: a = 7.506(3) Å, b = 9.041(5) Å, c = 5.927(7) Å
Crystal Habit: As enantiomorphous bladed crystals exhibiting {011}, {111}, {111}, {010} and several other forms, sometimes forming scepters. Also as radially fibrous crusts and nodules.
Twinning: Left- and right-handed individuals joined on (100), with (010) and (001) coincident.
Color: Colorless, white to pale yellowish white, green
Diaphaneity: Translucent to transparent
Luster: Sub-adamantine to silky in aggregates
Hardness (Mohs): 4 - 4.5
Measured Density: 4.13 g/cm3
Cleavage: Good on {011}
Tenacity: Brittle
Polymorphism and Series: Forms a series with conichalcite.
Geologic Setting: A rare secondary mineral in the oxidized zone of some arsenic-rich base-metal deposits.
Mineral Association: Adamite, talmessite, “limonite”, quartz (Gold Hill, Utah, USA)
Comments: The zinc analogue of cobaltaustinite and nickelaustinite.