Ilvaiet, Ilvait, Ilvaít, Ilvaita, Ilvaitas, Ільваїт, Ильваит, 珪灰鉄鉱, 黑柱石, อิลวาไอต์, אילוואיט

Commonly known      rarer (so called collectors stones)      very rare (rarities)      relatively rare organic material

Formula: CaFe22+Fe3+OSi2O7(OH)
Mineral class: silicates
Crystal system: orthorhombic or monoclinic
Mohs scale: 5.5 - 6
Density (g/cm3): 3.99 - 4.05
Refractive index: 1.727 - 1.883
Cleavage: good
Colors: black
Luster: submetallic
Fluorescence: -
Pleochroism: strong. X: dark green, Y: brown, Z: brown
Largest crystal: 25 cm?
Deposits: worldwide
Discovery: 1811
1st Description: 1811
Name: after the Latin word for the Italian island Elba (Ilva), the type locality

Ilvaite Mineral

Size: 3.4 x 1.2 x 0.9 cm

Origin: Koundouro / Serifos Island / Aegean Isl. Pref. / Greece

Photo by kind permission of ©
Ilvaite Mineral


Size: 1.43 x 0.85 cm
Weight: 9.68 ct
Origin: Greece

Photo by kind permission of ©

⇐ Intro Page ⇐ Gemstones