Abhurite

Abhurite is a mineral of tin, oxygen, hydrogen, and chlorine with the formula Sn₂₁O₆(OH)₁₄Cl₁₆^[4][2] or Sn₃O(OH)₂Cl₂.^[5] It is named after its type locality, a shipwreck with tin ingots at Sharm Abhur, a cove near Jeddah in the Red Sea. Abhurite forms alongside other tin minerals like romarchite and cassiterite.^[6] Abhurite can vary in color, from pale green/yellow to darker brown/green^[7]

Abhurite
Brownish tabular crystals of abhurite from Shipwreck "Hydra", South coast of Norway
General
Category	Halide mineral
Formula	Sn21O6(OH)14Cl16
IMA symbol	Abh[1]
Strunz classification	3.DA.30
Crystal system	Trigonal
Crystal class	Trapezohedral (32) H-M symbol: (32)
Space group	R3 2
Unit cell	a = 10.0175 Å, c = 44.014 Å; Z=3
Identification
Color	Colorless/Pale yellow-greenish
Crystal habit	Platy, thin crystals, cryptocrystalline crusts
Twinning	On 0001
Cleavage	None
Fracture	Hackly
Tenacity	Fragile
Mohs scale hardness	2
Streak	White
Diaphaneity	Transparent
Specific gravity	4.42
Density	4.42 g/cm3 (Measured) 4.417 g/cm3 (Calculated)
Optical properties	Uniaxial (+)
Refractive index	nω = 2.060 nε = 2.110
Birefringence	δ = 0.050
Other characteristics	opalescent
References	[2][3][4]

Locality and formation

Abhurite is attributed for forming on tin materials when in contact with sea water. The mineral was described in 1977 from a shipwreck near Hidra Island, Norway, where it occurred on pewter plates. However, that report was not recognized by the International Mineralogical Association.^[2] Along with Sharm Abhur and the shipwreck near Hidra Island, abhurite was found on tin ingots in the Uluburun shipwreck. On the ingots, it was found with other tin minerals like cassiterite and romarchite, and calcium carbonate minerals like calcite and aragonite.^[8]

See also

• List of minerals