Milarite Value, Price, and Jewelry Information


MILARITE: Tsumeb, Namibia (0.53). Photo © Joel E. Arem, PhD, FGA. Used with permission.

Milarite was originally known as a green mineral, until fine yellow crystals were discovered in Mexico in 1968. Larger Mexican crystals have transparent areas and have been faceted into small gems of pleasant appearance but great rarity.

Milarite Value

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Milarite Information

DataValue
NameMilarite
Crystallography Hexagonal. Crystals prismatic and tabular; in grains.
Colors Colorless, pale green, yellowish, yellowish green.
Luster Vitreous.
Fracture Conchoidal to uneven; brittle.
Hardness 5.5-6.
Specific Gravity 2.46- 2.61.
Birefringence 0.003.
Cleavage None.
Stone SizesCrystals occur up to about 4 cm across, but facetable areas in such crystals are very small. Stones over 1 carat could be considered large for the species.
Luminescence None.
Spectral Not diagnostic.
FormulaK2Ca4Be4Al2Si24O60·H2O.

Osumilite Group.

Optics: o=1.532-1.551: e = 1-529-1-548

Uniaxial (—).

Occurrence: In vugs in granites and syenites: hydrothermal veins.

St. Gotthard, Switzerland: green crystals.

Guanajuato, Mexico: yellow and yellow green crystals on matrix, flat, platelike.

Africa: occasional small facetable crystals found.

Comments: Milarite was originally known as a green mineral, until fine yellow crystals were discovered in Mexico in 1968. Larger Mexican crystals have transparent areas and have been faceted into small gems of pleasant appearance but great rarity.

Name: After the Val Milar, Switzerland, because the mineral was (mistakenly) thought to have occurred there.