Ilvaite
Ilvaite
Published: June 2014
Modified: August 2021
Ilvaite is name after the “Ilva” the Latin name for the island of Elba, Italy. It is black and forms in prismatic columns or large masses of indistinguishable crystals.
General Information
Common Name
Ilvaite
Species
Ilvaite
Transparency
Opaque
Dispersion
Strength: Strong Fire
Refractive Index
1.727-1.883
Birefringence
0.156
Optic Character
Biaxial
Optic Sign
Positive
Polariscope Reaction
Aggregate (AGG), Doubly Refractive (DR)
Fluorescence
SWUV: Inert
LWUV: Inert
LWUV: Inert
Pleochroism
Trichroic, green, yellowish brown, brown
Hardness
5.5-6
Streak
Black with greenish or brownish tint
Specific Gravity
3.800-4.100
Toughness
Poor
Luster
Metallic, Greasy, Vitreous
Stability
Brittle
Fracture
Uneven, conchoidal
Cleavage
Incomplete
Chemical Name
sorosilicate of iron and calcium
Chemical Formula
CaFe2+2Fe3+O(OH)(Si2O7)
Crystal System
Orthorhombic
Chemistry Classification
Silicate
Ilvaite Colors
-
Black
Countries of Origin
Czechia; Kazakhstan; Iceland; Greece; Austria; Mongolia; Sweden; Morocco; Unknown; China; Russian Federation (the); Brazil; Poland; Slovakia; Bulgaria; Chile; France; United Kingdom of Great Britain and Northern Ireland (the); Argentina; Romania; United States of America (the); Republic of Kosovo; Japan; Ukraine; Switzerland; Bolivia (Plurinational State of); India; Spain; New Zealand; Canada; Turkey; Norway; Namibia; Italy; Mexico; South Africa; Australia; Germany; Greenland; Tajikistan
Care
Easily soluble in HCL.