Titanite

Titanite, traditionally and still popularly called sphene, is a calcium titanium silicate (CaTiSiO5). The name sphene comes from the Greek for "wedge," describing its typical wedge-shaped monoclinic crystals.

Its standout gem property is exceptional dispersion (fire) that actually surpasses that of diamond, giving faceted stones intense flashes of spectral color. Combined with high luster and rich green, yellow, orange, and brown body colors, this makes gem sphene a favorite among collectors.

As a common accessory mineral, titanite is also an important indicator of titanium in many rocks and is used in geochronology.

Titanite is a widespread accessory mineral in igneous rocks such as granites, syenites, and diorites, and in metamorphic rocks including gneisses, schists, and skarns. Gem-quality crystals often come from metamorphic and alpine-fissure environments where slow growth produces clear material.

It forms wedge-shaped or flattened monoclinic crystals, commonly with calcite, feldspar, chlorite, epidote, and amphiboles. Notable gem and specimen localities include the Alps, Pakistan, Madagascar, Brazil, Mexico, Russia, and Canada (Ontario and Quebec).

Key clues are intense fire (dispersion stronger than diamond), high adamantine to resinous luster, and typical yellow-green to brown colors, often in wedge-shaped crystals. The hardness is fairly low for a gem (Mohs 5-5.5), and the streak is white.

Gemologically, titanite shows strong birefringence (visible facet doubling) and high refractive index. Look-alikes include peridot, chrysoberyl, and zircon, but titanite's combination of low hardness, extreme fire, and strong doubling is distinctive. Its softness means faceted stones show wear sooner than harder gems.

As a gemstone (sphene), titanite is cut for collectors and connoisseurs who prize its fire and color; the vivid green chrome-bearing material is especially valued. Because of its softness and easy cleavage, it is best used in earrings, pendants, and protected settings rather than rings subject to abrasion.

Industrially, titanite is a minor potential source of titanium and is important in petrology and U-Pb geochronology for dating rocks. Metaphysically it is sometimes linked to mental clarity and energy, though its main appeal is gemological and scientific.