“Samarskite – Y,” Setesdal, Aust-Agder County, Norway. © Rob Lavinsky, www.iRocks.com. Used with permission.
Samarskite is a very heavy material from which lustrous black to brownish cabochons are sometimes cut as curiosities. The material is rather brittle and is not intended for wear. It is rarely seen or displayed since black stones are not terribly attractive. Sometimes a stone is faceted in the nature of jet or marcasite.
| Data | Value |
|---|---|
| Name | Samarskite |
| Colors | Velvety black, yellowish brown on exterior. |
| Crystallography | Monoclinic. Crystals rough, tabular: massive, compact. |
| Refractive Index | 2.20 |
| Luster | Dull after alteration; resinous; vitreous, submetallic. |
| Hardness | 5-6 |
| Fracture | Conchoidal |
| Specific Gravity | 5.25-5.69 (variable), usually near upper end of range. |
| Cleavage | Indistinct |
| Stone Sizes | Large cabochons can be cut from masses found at various localities. This material is essentially opaque. |
| Luminescence | None. |
| Luminescence Present | No |
| Transparency | Opaque. |
| Formula |
(Y, Ce, U, Ca, Pb)(Nb,Ta,Ti,Sn)2O6 |
| Pleochroism |
None. |
| Optics |
Isotropic; N = 2.20 (variable). Isotropic nature caused by metamictization. |
SAMARSKITE See also: Euxenite, Fergusonite.
Samarskite Information
Streak: Black to reddish brown.
Optics: Isotropic; N = 2.20 (variable).
Isotropic nature caused by metamictization.
Occurrence: A widespread pegmatite mineral.
North Carolina; Colorado.
USSR; Norway; Madagascar; Zaire; Japan; Minas Gerais, Brazil; Madras. India.
Comments: Samarskite is a very heavy material from which lustrous black to brownish cabochons are sometimes cut as curiosities. The material is rather brittle and is not intended for wear. It is rarely seen or displayed since black stones are not terribly attractive. Sometimes a stone is faceted in the nature of jet or marcasite.
Name: ln honor of Colonel Samarski, a Russian mining official.
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