Ajoite

Ajoite is a rare and beautiful mineral that is usually found in association with other rare secondary copper minerals such as Papagoite and Shattuckite. A single specimen containing these minerals together is an amazing and beautiful combination of colors. Ajoite forms as excellent microcrystal specimens and occassionally as relatively large masses or veins in Quartz that can be fassioned into beautiful cabochons.

Ajoite is only found in a few locations worldwide. Of course it is found at the type locality New Cornelia Mine, Ajo, Pima County, Arizona and also at Wickenburg, Maricopa County, Arizona, USA; Munihuaza, near Alamos, Sonora, Mexico; and Messina, Transvaal, South Africa.

Chemical Formula:	(K;Na)Cu7AlSi9O24(OH)6 · 3(H2O)
	Hydrated Potasium Sodium Copper Aluminum Silicate Hydroxide
Molecular Weight:	3,926.74 gm

Composition:	Potassium	2.24 %	K	2.70 %	K2O
	Sodium	1.02 %	Na	1.38 %	Na2O
	Aluminum	2.06 %	Al	3.89 %	Al2O3
	Copper	32.37 %	Cu	40.51 %	CuO
	Silicon	20.74 %	Si	44.37 %	SiO2
	Hydrogen	0.82 %	H	7.34 %	H2O
	Oxygen	40.74 %	O
		100.00 %		100.00 %	= TOTAL OXIDE

Crystallography:	Triclinic – Pinacoidal
Crystal Habit:	As sprays of bladed prismatic crystals, to 0.4 mm; commonly fibrous; Lath – Shaped like a small, thin plaster lath, tabular (rectangular) in shape; Massive – Uniformly indistinguishable crystals forming large masses; Platy – Sheet forms (e.g. micas)
Twinning:	None

Cleavage:	Perfect on [010]
Fracture:	n/a
Tenacity:	Brittle
Moh’s Hardness:	3.5
Density:	2.96 (g/cm3)
Luminescence:	None
Radioactivity:	Barely Detectable; GRapi = 31.60 (Gamma Ray American Petroleum Institute Units)

Color:	Bluish Green, Light Green
Transparency:	Translucent
Luster:	Vitreous (Glassy)
Refractive Index:	1.550 – 1.641  Biaxial ( + )
Birefringence:	0.0910
Dispersion:	Strong, r < v
Pleochroism:	Visible; X = very light bluish green; Y = Z = brilliant bluish green