Clinohumite: The mineral clinohumite information and pictures

About

Clinohumite is a member of the humite group, and is chemically similar to Humite, with a very slightly modified chemical formula and different crystal form. Though Clinohumite is not a common mineral, it occurs more frequently and in better examples than its namesake Humite.

Crystal Forms & Aggregates

Crystals may be tabular and prismatic, usually as complex crystals with rounded faces. Crystals may also be twinned in a vertical plane. Most frequently in grainy and crude masses.

Other ID Marks

May fluoresce yellow to orange in shortwave ultraviolet light.

Striking Features

Color, crystal habits, and mode of occurrence

Environment

In marble deposits of metamorphosed limestones and dolomites.

Varieties

✓ common · ✗ uncommon

Hydroxylclinohumite— Form of Clinohumite lacking fluorine it its chemical structure, containing only hydroxyl at the end of its chemical formula. Hydroxylclinohumite is also deficient in iron, which is usually present in Clinohumite. Hydroxylclinohumite was classified in 1998 and is considered an individual mineral by the IMA.

Uses

Clinohumite is of interest to collectors, especially the rare transparent forms which are highly collectible. Gems for collectors are ocassionally cut from transparent stones.

Noteworthy Localities

The best formation of Clinohumite, in the form of outstanding orange crystals with good transparency, is from Kukh-i-Lal, Pamir Mts, Tajikistan. Sharp crystals and grains of Hydroxylclinohumite of excellent quality come from Sar-e-Sang, Kokcha Valley, Badakhshan Province, Afghanistan. Clinohumite associated with contrasting dark Spinel is found in the Hunza Valley, Gilgit, Pakistan.
Gemmy Clinohumite microcrystals have been found at Monte Somma, Vesuvius, Italy; and orange crystal grains from the Málaga region, Andalusia, Spain. In the U.S., large crystal clusters, almost always associated with Spinel, were found at the Rudy farm locality, Edenville, Orange Co., New York. In Canada, large Clinohumite crystals, including rare twinned crystals, have come from a one-time find at Essonville Line, near Wilberforce, Haliburton Co.