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Phosphate

Florencite-(Sm)

SmAl₃(PO₄)₂(OH)₆
Hardness5.5–6
Crystal systemHexagonal
ClassPhosphate
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Florencite-(Sm)

Florencite-(Sm) is a very rare mineral of the plumbogummite group (alunite supergroup) with simplified formula SmAl3(PO4)2(OH)6. Samarium in florencite-(Sm) is substituted by other rare earth elements, mostly neodymium. It does not form separate crystals, but is found as zones in florencite-(Ce), which is cerium-dominant member of the plumbogummite group. Florencite-(Sm) is also a samarium-analogue of florencite-(La) (lanthanum-dominant) and waylandite (bismuth-dominant), both being aluminium-rich minerals.

Intro adapted from Wikipedia (CC BY-SA).

Florencite-(Sm) is an IMA-recognized mineral species in the phosphate class, with the chemical formula SmAl₃(PO₄)₂(OH)₆.

It crystallizes in the hexagonal crystal system (space group R-3m). It is a member of the Alunite-crandallite structural group.

Key properties: Mohs hardness 5.5–6; specific gravity 3.6; White streak; Vitreous to greasy luster; optically uniaxial.

IMA symbol Flo-Sm, IMA status: approved, named in 2009.

Found in quartz veins cutting quartz meta-conglomerate beds near contacts with Al-enriched metasomatites.

It is found associated with Florencite-(Ce), xenotime-(Y), quartz, dravite.

As the Sm-dominant example of the florencite structure.

Index entry. This entry combines official IMA/RRUFF species data with published physical-property data and a Wikipedia introduction — a full written entry hasn’t been published yet. Browse more F minerals or help write this entry.