ANGLESITE: Morocco (6.99)
Anglesite gems are colorless to pale brown and are available from only a few localities. The dispersion is equal to that of diamond, and property faceted gems are truly magnificent and bright. Low hardness and cleavage indicate great care is requires in cutting, and wear is not recommended. Cut anglesites are true rarities and seldom seen except in very complete collections.
Anglesite Value
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Anglesite Information
| Data | Value |
| Name | Anglesite |
| Crystallography | Orthorhombic. Crystals usually tabular, prismatic; granular; massive; stalactitic. |
| Colors | Colorless, white yellowish gray, lemon to golden yellow, brownish orange pale green, and bluish shades. |
| Luster | Adamantine to vitreous. |
| Hardness | 2.5-3 |
| Density | 6.30-6.39; usually 6.38 |
| Birefringence | 0.017 |
| Cleavage | Good 1 direction. Fracture conchoidal. Brittle. |
| Dispersion | 0.044 |
| Stone Sizes | The usual range is 1-6 carats for faceted gems. Anglesites very rarely are large enough to cut bigger stones than this, but some rough has yielded 100+ carat gems, notably the material from Tsumeb (note: A 300-carat, stone broke during cutting!) and Morocco. DG: 88.75 (yellow, coffin-shaped triangle, Tsumeb, Namibia) ROM: 23.62 (colorless, step cut, Tsumeb) NMC: 25.90 (yellow, scissors-cut, Morocco). PC: 126 (light golden brown, Morocco) 73 (yellow orange, cushion cut, Morocco) 63 (lemon yellow emerald cut, Morocco) 171.12 (medium orange, Morocco) 169 (oval, Morocco) |
| Luminescence | Weak yellowish fluorescence in SW and LW |
| Spectral | Not diagnostic |
| Formula | PbSO4 |
| Pleochroism | None |
Optics: α = 1.877 ; β = 1.883 γ= 1.894.
Biaxial (+), 2V ~75°
Occurrence: Secondary mineral in lead deposits, formed by oxidation of galena (PbS). There are many localities, and many have the potential of yielding gemmy crystals.
Chester County, Pennsylvania; Tintic, Utah; Arizona; New Mexico; Coeur d’Alene district, Idaho.
Chihuahua, Mexico; England; Scotland; Wales; USSR; Germany, Sardinia; Broken Hill, N.S.W., Australia; Dundas, Tasmania.
Morocco: gem crystals from Touissit, in immense sizes for the species.
Tsumeb, Namibia: large transparent yellowish crystals, sometimes colorless, gemmy.
Tunisia: gemmy crystals.
Comments: Anglesite gems are colorless to pale brown and are available from only a few localities. The dispersion is equal to that of diamond, and property faceted gems are truly magnificent and bright. Low hardness and cleavage indicate great care is requires in cutting, and wear is not recommended. Cut anglesites are true rarities and seldom seen except in very complete collections.
Names: Anglesey, the English locality where first found.
