Formula: CaFe3+Fe2+2(Si2O7)O(OH)

Colour: Iron-black, dark grayish black

Lustre: Sub-Metallic

Hardness: 5½ – 6

Specific Gravity: 3.99 – 4.05

Crystal System: Orthorhombic

Member of: Lawsonite Group

Name: For “Ilva”, the old latin name of Elba Island, on which the co-type localities are situated.
The history of the name of ilvaite is complex. The mineral was probably first observed in 1784 by the french geologist Déodat de Dolomieu (1750-1801) during his voyage to the Elba Island, Italy. The french mineralogist Romé de l’Isle (1736-1790) also had a crystal of the mineral in collection, labelled as Mine de fer noirâtre attirable à l`aimant [an iron mineral that is attracted by magnet] and originating from Rio Marina. It was analyzed by the french chemist Vaquelin. But it was first published, described and named in 1807 by the French mineralogist Claude-Hugues Leliévre (1752-1835). He named it as yenite, in memory of the battle at Jena. The battle was between the forces of Napoleon I of France and Frederick William III of Prussia.The name should have been written Jenite, but according to Leliévre he changed it to Yenite, to avoid confusions with the prononciation. The name was however criticized in the science community. Information on the new mineral was published by french geologist Jean-François D’Aubuisson in 1807. Later the German/Danish-Norwegian philosopher and mineralogist Henrik Steffens (1773-1845) introduced the name Ilvaite.Later, in 1812 another German, Abraham Gottlob Werner proposed the name Lievrite in honor of Leliévre who first described the mineral. The name Ilvaite is the name used today.

Co-Type Localities: Cape Calamita Mine (Calamita Mine), Capoliveri, Livorno Province, Tuscany, Italy. Torre di Rio – Santa Filomena area (Monte della Torre), Rio Marina, Rio, Livorno Province, Tuscany – Italy

A sorosilicate. The ferrous iron analogue of manganilvaite.