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Gemstones 250x250

The Mineral titanite

Pointed Green Titanite Crystal

Titanite is frequently called by the name Sphene, which was the more popular term for this mineral prior to 1982. In 1982, the IMA adopted the official name as Titanite and discredited Sphene. The name Sphene is still frequently used, especially in Europe. Sphene also persists as the more prevalent name for faceted Titanite gemstones or transparent crystal forms.

Titanite is known for its high luster and dispersion rate. This results in transparent Titanite crystals being brilliant, and opaque Titanite being highly reflective. It is also pleochroic, with different transparent crystals exhibiting different hues when viewed at different angles.  

Titanite from a few localities contains thorium within its chemical structure. Such Titanite is slightly radioactive and will be metamict, resulting in those crystals having slightly rounded crystal edges and interior structural deficiencies.

Titanite is named for its titanium content. Its alternate name Sphene is named from the Greek term "sphenos", which means wedge, in allusion to the typical wedge-shaped crystals exhibited by this mineral.

For additional information, see the gemstone section on Sphene.

Chemical Formula

CaTiSiO5

Color

Light to dark brown, orange, yellow, yellowish-green, olive-green, emerald-green, greenish-brown. Rarely white, colorless, gray, pink, or purple. May have color zones with lighter to darker browns.

Crystal System

Monoclinic

Properties

Streak
White
Hardness
5 - 5.5
Transparency
Transparent to opaque
Specific Gravity
3.4 - 3.6
Luster
Adamantine, greasy
Cleavage
2,2. Parting along crystal planes and twins is common.
Fracture
Conchoidal
Tenacity
Brittle

Crystal Habits

Crystals are usually as sharply angled, wedge shaped crystals. Crystals may be in flattened tabular form, in prismatic crystals with pointed terminations, and in complex dipyramidal crystals. Twinning is common as repeated twins. May also be grainy, massive, and in rounded waterworn floater crystals. Crystals are sometimes striated or naturally etched.

3D Crystal Atlas

Additional Information

Composition
Calcium titanium silicate. Rare earth elements such as thorium, cerium, and yttrium are sometimes present in minor quantities.
In Group
Silicates; Nesosilicates
Striking Features
Crystal habits, luster, and mode of occurrence
Environment
In metamorphic rocks such as marble, gneiss, schist, and skarns, and especially in contact zones. Also in hydrothermal replacement deposits, in altered diabase and granite, and in nepehline syenite pegmatites. A common member of alpine-type environments. Occasionally also in alluvial deposits.
Rock Type
Igneous, Metamorphic

Other Names

Sphene

Varieties

 -   Emerald-green, chromium-rich variety of Titanite
 -   A pink to red, manganese-rich variety of Titanite.
 -   Describes either an aluminum-bearing Titanite, or a form of Titanite containing Titanite containing yttrium or cerium.
 -   A rare-earth bearing Titanite rich in yttrium.
 -   Yellow, earthy Anatase pseudomorph after Titanite.

Uses

Titanite is an important collector's mineral, with well-formed crystals and transparent varieties being particularly desirable. It is also used as a minor gemstone. Titanite is industrially important as a source of titanium dioxide, (TiO2), which is used in pigments.

Noteworthy Localities

Exceptionally large and gemmy green Titanite crystals come from several alpine-type deposits in the Skardu district, Gilgit-Baltistan, Pakistan, especially at the Shigar and Tormiq Valleys.

The alpine cavities of the European Alps in Austria, Italy, and Switzerland have produced many fine Titanite crystals. While most localities have only produced small crystals, several localities are noted for large, well-formed crystals. In Austria, gemmy, olive-green Titanite crystals have come from the Felbertal and Habachtal, Hohe Tauern, Salzburg; large green and brown crystals from the Zillertal, North Tyrol; and yellowish-green crystals with contrasting white Albite and Quartz from Törlkopf and Mallnitz, Carinthia. In Switzerland, twinned pointy Titanite crystals, sometimes elongated, come from Tujetsch, Grischun; and green as well as a rare violet Titanite comes from the St Gotthard Massif, Ticino.

In Russia, an Emerald-green "Chrome Titanite" is described from the Saranovskii Mine, Sarany, in the Ural Mountains; and twinned dark brown crystals from the Dodo Mine, Saranpaul, Khanty-Mansi Okrug.

In Africa, lustrous brown and green Titanite crystals are found in Imilchil, Morocco; and olive-green, transparent, flattened twins come from Ankarafa, Antsiranana Province, Madagascar.

Brazil has produced exceptionally large, gemmy, olive-green green crystals that are often twinned at Capelinha, Minas Gerais.

In the U.S., greenish-brown Titanite crystals, sometimes coated with Chlorite, have come from the Acushnet Quarry, Bristol Co., Massachusetts. Sharp brown crystals with highly reflective surfaces are found in New York at Amity, Orange Co.; as well as several as several localities in the Adirondacks such as Rossie and Oxbow, St. Lawrence Co.; and Natural Bridge, Lewis Co. Small yellow transparent crystals are classics from the Tilly Foster Mine, Brewster, Putnam Co., New York.

In Canada, large, sharp, dark brown crystals have come from Ontario at Eganville and Sebastopol Township, Renfrew Co; and at Wilberforce and Bear Lake, Haliburton Co.

Distingushing Similar Minerals

Axinite - Lower specific gravity, greater hardness.
Sphalerite - Different crystal forms, lower hardness.
Staurolite - Different crystal form and twinning habits, duller luster.
Zircon - Different crystal form, greater hardness.
Green Datolite - Lower specific gravity, usually in stubbier crystals.


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