“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 |
| Stone Sizes | Large cabochons can be cut from masses found at various localities. This material is essentially opaque. |
| Formula | (Y, Ce, U, Ca, Pb)(Nb,Ta,Ti,Sn)2O6 |
| Colors | Velvety black, yellowish brown on exterior. |
| Fracture | Conchoidal |
| Hardness | 5-6 |
| Cleavage | Indistinct |
| Crystallography | Monoclinic. Crystals rough, tabular: massive, compact. |
| Crystallographic Forms | |
| Refractive Index | 2.20 |
| Birefringence | None. (Isotropic due to metamictization). |
| Luminescence | None. |
| Luminescence Present | No |
| Pleochroism | None. |
| Optics | Isotropic; N = 2.20 (variable). Isotropic nature caused by metamictization. |
| Luster | Dull after alteration; resinous; vitreous, submetallic. |
| Specific Gravity | 5.25-5.69 (variable), usually near upper end of range. |
| Transparency | Opaque. |
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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