Aeschynite-(Nd) Knowpia

Aeschynite-(Nd)
Aeschynite-(Nd)
General
Category	Mineral
Formula; (repeating unit)	(Nd,Ce,Ca,Th)(Ti,Nb)2(O,OH)6
IMA symbol	Aes-Nd
Strunz classification	4.DF.05
Dana classification	8.3.6.5
Crystal system	Orthorhombic
Crystal class	Dipyramidal (mmm) ; H-M symbol: (2/m 2/m 2/m)
Identification
Formula mass	346.61 gm
Color	Dark to pale brown, brownish black
Crystal habit	Metamict
Fracture	Conchoidal
Tenacity	Brittle
Mohs scale hardness	5 – 6
Luster	Adamantine
Streak	Pale yellowish brown
Diaphaneity	Subtranslucent
Specific gravity	4.60 – 5.04
Density	4.6 – 5.04 g/cm3
Optical properties	2.1 – 2.4
2V angle	78° – 82°
Dispersion	Weak to strong

Aeschynite-(Nd) is a rare earth mineral of neodymium, cerium, calcium, thorium, titanium, niobium, oxygen, and hydrogen with the chemical formula (Nd,Ce,Ca,Th)(Ti,Nb)₂(O,OH)₆. Its name comes from the Greek word for "shame". Its Mohs scale rating is 5 to 6. It is a member of the hydroxide minerals.

It was first reported for an occurrence in Bayan Obo, Inner Mongolia in 1982. In that rare earth mining deposit it occurs in veins within metamorphosed dolomite and slate. It occurs associated with aegirine, riebeckite, barite, fluorite, albite, phlogopite and magnetite.^[1] The IMA symbol is Aes-Nd.^[2]

References edit

^ Handbook of Mineralogy
^ 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.