saf-ahyuh r

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.

Ilvaite Polished
Ilvaite Classification
Common Name Ilvaite
Species Ilvaite
Ilvaite Optical Properties
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
Pleochroism Trichroic, green, yellowish brown, brown
Ilvaite Characteristic Physical Properties
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
Ilvaite Chemistry & Crystallography
Chemical Name sorosilicate of iron and calcium
Chemical Formula CaFe2+2Fe3+O(OH)(Si2O7)
Crystal System Orthorhombic
Chemistry Classification Silicate

Ilvaite Colors

  • Black Ilvaite Black

Countries of Origin

Czechia; Kazakhstan; Iceland; Greece; Austria; Mongolia; Sweden; Morocco; 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


Easily soluble in HCL.

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Tim Matthews


Tim Matthews

Tim Matthews is President and Chief Executive Officer of Jewelry Television® (JTV), as well as a member of the company's Board of Directors. He oversees and leads all aspects of the company's powerful omni-digital retail platform that uniquely specializes in fine jewelry and gemstones. His passion for business and gemstones has led him to become a recognized expert in the field of gemology. He is a life member of the Gemmological Association of Great Britain (Gem-A) and has earned Gem-A's highest degrees, the Gemmology (FGA) and Diamond (DGA) diplomas. He is also a Graduate Gemologist (GG) of the Gemological Institute of America (GIA) and has also completed GIA's Graduate Diplomas in Diamonds, Colored Stones and Pearls. Under his leadership, JTV has become the leader in the sourcing and selling of color gemstones and jewelry.

This page was created on June 27, 2014.

This page was last edited on October 24, 2019.