rubrit

Rubrit is a rare mineral in the oxide class, notable for its deep red color and high clarity in transparent crystals. It forms in hydrothermal veins within granitic rocks and is sought by mineral collectors for its distinctive hue and luster.

The name Rubrit combines the Latin ruber, meaning red, with the suffix -it common to mineral names, and references the fictional Rubria Range where the type material was described.

Chemically, rubrit is an iron- and chromium-rich oxide with minor titanium and vanadium. It crystallizes in the orthorhombic system and occurs as tabular prisms and blocky aggregates. The luster is vitreous; color is deep crimson to reddish-brown; transparency ranges from transparent to translucent. Mohs hardness is 6.5–7; specific gravity about 3.8–4.2.

Occurrence: The principal source is a small deposit in the Rubria Range, with associations quartz, magnetite, and rutile. It forms in late-stage hydrothermal environments within silica-rich pockets of granitic host rocks.

Use and significance: Rubrit is extremely rare and has limited practical applications. It is mainly valued by collectors and researchers. If larger and sufficiently transparent, it could be cut as a gemstone, but brittleness and scarcity limit commercial viability.

See also: List of minerals; Oxide minerals; Rubria Range.