Natrophilite

Natrophilite
Natrophilite, as thin coatings and fracture fillings, from Branchville, Redding, Fairfield County, Connecticut, US
General
Category	Phosphate mineral
Formula	NaMnPO4
IMA symbol	Ntp[1]
Strunz classification	8.AB.10
Crystal system	Orthorhombic
Crystal class	Dipyramidal (mmm) H-M symbol: (2/m 2/m 2/m)
Space group	Pnam
Identification
Color	Deep yellow to light yellow
Cleavage	Distinct/ good
Fracture	Irregular/ uneven
Tenacity	Brittle
Mohs scale hardness	4+1⁄2 – 5
Luster	Sub-vitreous, greasy
Streak	White
Diaphaneity	Transparent, translucent
Specific gravity	3.41 g/cm^3

Natrophilite is a mineral with the chemical formula NaMnPO₄. In a pure form it has a yellow coloration. Its crystals are orthorhombic to dipyramidal. It is transparent to translucent. It is not radioactive. Natrophilite is rated 4.5 to 5 on the Mohs Scale. At Branchville, Fairfield County, Connecticut, it is found as a rare replacement of lithiophilite within a complex granite pegmatite, together with triploidite, eosphorite and dickinsonite.^[2]

References

1. Warr, L.N. (2021). "IMA–CNMNC approved mineral symbols". Mineralogical Magazine. 85 (3): 291–320. Bibcode:2021MinM...85..291W. doi:10.1180/mgm.2021.43. S2CID 235729616.
2. "Natrophilite" (PDF). Handbook of Mineralogy. Mineral Data Publishing. Retrieved 10 September 2026.

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