Angelite

Angelite is a trade title for a translucent to opaque, a light variety that is blue of marketed being a treasured material. Angelite is called for the “angelic” light blue to colour that is lilac-blue. Anhydrite is known as from the Greek word anhydrous meaning without water, in allusion to the lack of water in its structure, in comparison to Gypsum, which contains water.

Anhydrite is a relatively common mineral that is sedimentary is the result of dewatering of the rock forming mineral Gypsum. Good crystal specimens of Anhydrite are incredibly rare so gems that are faceted additionally extremely unusual. However, fine semi-translucent to opaque specimens of Angelite have actually been present in Mexico and Peru that have a fine colour that is blue.

 

Chemical Formula:	CaSO4
	Calcium Sulfate
Molecular Weight:	136.14 gm

Composition:	Calcium	29.44 %	Ca	41.19 %	CaO
	Sulfur	23.55 %	S	58.81 %	SO3
	Oxygen	47.01 %	O
		100.00 %		100.00 %	= TOTAL OXIDE

 

Crystallography:	Orthorhombic – Dipyramidal
Crystal Habit:	Crystals tabular on {010}, {100}, or {001} or equant with large pinacoid faces; elongated along [100] or [001], to 15 cm, with about 40 forms recorded. Typically granular, nodular, parallel or divergent fibrous, massive. Contorted concretionary forms (Bowel Stone).
Twinning:	Simple or repeatedly on {011}, common; contact twins rare on {120}.

 

Cleavage:	Perfect on {010}, nearly Perfect on {100}, Good to Imperfect on {001}; yielding pseudocubic fragments.
Fracture:	Irregular/Uneven, Spintery
Tenacity:	Brittle
Moh’s Hardness:	3.0 – 3.5
Density:	2.96 – 2.98 (g/cm3)
Luminescence:	Occassionally red under LW UV
Radioactivity:	Not Radioactive

 

Color:	Light Blue, light Lylac-Blue, Grayish-Blue
Transparency:	Translucent, Opaque
Luster:	Pearly on {010}, Vitreous to Greasy on {001}; Vitreous on {100}.
Refractive Index:	1.567 – 1.618  Biaxial ( + )
Birefringence:	0.0420 – 0.0440
Dispersion:	Strong; r < v
Pleochroism:	None