Hellandite-(Y)

Overview

(Ca,REE)4(Y,Ce)2(Al,Be,Li)2(Si4B4O22)(OH)2
Fluorescence: none	Mildly Radioactive	Magnetic: no

Description

Physical Properties

Property	Value
Density	3.7 g/cc
Hardness - Mohs	Hellandite-(Y) - 5.5-6.0  10 Diamond 9 Carborundum 8 Topaz 7 Quartz 6 Orthoclase 5 Apatite 4 Fluorite 3 Calcite 2 Gypsum 1 Talc
Color	yellow, black, brown
Streak	-

Crystal Properties

Property	Value
Crystal structure	monoclinic - prismatic
Cleavage	poor
Tenacity	brittle
Fracture	conchoidal
Luster	vitreous, greasy

Similar Minerals

Dana Number : 54.02.02.01

Class: 54

Group: 54.02

Subgroup: 54.02.02 - hellandite

Dana Number	Mineral Name	Formula
54.02.02.01	hellandite-(Y)	(Ca,REE)4(Y,Ce)2(Al,Be,Li)2(Si4B4O22)(OH)2
54.02.02.03	tadzhikite-(Ce)	Ca4(Ce,Y)2(Ti,Al,Fe+3)2(Si4B4O22)(OH)2

Nickel-Strunz Number : 09.DK.20

Group : 09

Subgroup : DK

Nickel-Strunz Number	Mineral Name	Formula
09.DK.20	hellandite-(Y)	(Ca,REE)4(Y,Ce)2(Al,Be,Li)2(Si4B4O22)(OH)2
09.DK.20	tadzhikite-(Ce)	Ca4(Ce,Y)2(Ti,Al,Fe+3)2(Si4B4O22)(OH)2

Specimens

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Uses