Lulzacite | |
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![]() Lulzacite found in France | |
General | |
Category | Phosphate minerals |
Formula | Sr2Fe2+(Fe2+,Mg)2Al4(PO4)4(OH)10 |
IMA symbol | Lul [1] |
Strunz classification | 8.BK.25 |
Crystal system | Triclinic |
Crystal class | Pinacoidal (1) (same H-M symbol) |
Space group | P1 |
Identification | |
Color | Grayish-green to yellowish-green |
Crystal habit | Anhedral aggregates; rarely small euhedral crystals |
Cleavage | None |
Mohs scale hardness | 5.5–6 |
Luster | Vitreous |
Diaphaneity | Transparent–translucent |
Specific gravity | 3.55 |
Optical properties | Biaxial (−) |
Refractive index | nα = 1.654 nβ = 1.674 nγ = 1.684 |
Birefringence | δ = 0.030 |
References | [2] [3] [4] |
Lulzacite is a strontium-containing phosphate mineral with the chemical formula Sr2Fe2+(Fe2+,Mg)2Al4(PO4)4(OH)10. [2] [3]
The mineral was first described in 2000 from quartzite deposits ( 47°42′50″N1°29′20″W / 47.71389°N 1.48889°W ) at Saint-Aubin-des-Châteaux, Loire-Atlantique, France, and is named after Y. Lulzac, a French geologist who discovered the mineral. In this deposit, lulzacite occurs within quartz and siderite veinlets at quartzite–limestone contacts. Other minerals found in the veinlets include apatite, goyazite, and pyrite. [4]
Lulzacite crystallizes in the triclinic system with P1 space group. It is isostructural with jamesite (Pb2Zn(Fe2+,Zn)2Fe3+4(AsO4)4(OH)10). [4] [5]