Chondrodite - Encyclopedia

    Class : Silicates
    Subclass : Nesosilicates
    Crystal system : Monoclinic
    Chemistry : Mg5(SiO4)2 (F,OH)2
    Rarity : Uncommon

Chondrodite is a mineral from the humite group. It is typical of limestones and dolomites affected by a contact metamorphism caused by plutonic and alkaline rocks which transformed them into cipolins or marbles. The genesis of chondrodite also requires significant metasomatosis (fluoride intake) ; the iron content does not exceed 10%. Chondrodite is also observed in carbonatites and in metamorphosed limestone blocks rejected by Italian volcanoes (beautiful 1 cm crystals perfectly formed at Vesuvius and Mount Somma, near Naples). It takes its name from the Greek khondros (grain) because of its frequent habit of rounded grains with a cracked appearance. More rarely, chondrodite forms isometric or tabular individual crystals, rich in faces, with shapes reminiscent of olivine. Twinning and aggregates are frequent, from yellow tinged with red to brown-red, even brown. It is a mineral occasionally cut into gemstones, the species remains little known to collectors.

Chondrodite from Koksha Valley, Badakhshan, Afghanistan

Chondrodite from Koksha Valley, Badakhshan, Afghanistan

Chondrodite from Koksha Valley, Badakhshan, Afghanistan

0.74 ct chondrodite from Tanzania

Chondrodite in the World

The famous Tilly Foster mine (New York) produced sumptuous red to orange-red gemmy crystals commonly reaching 2 cm and exceptionally 7 cm, associated with grossular, clinochlor and magnetite : these are the most beautiful crystals in the world. Other American mines like Franklin (New Jersey), provided beautiful crystals. The best occurrence of chondrodite in a carbonatite is from Palabora (South Africa) which produced 10 mm red gemmy crystals. Cipolins from Pargas (Finland), Ampotaka and Mahafaly (Madagascar) yielded yellow crystals, sometimes centimetric.

Chondrodite in France

In France, chondrodite is reported in several skarns and cipolins from the Pyrenees (Costabonne) and Vosges (Lime quarry).


Common on {001}.

Fakes and scams

No fake recorded for this mineral species.

Hardness : 6 to 6.5
Density : 3.16 to 3.26
Fracture : Conchoidal
Trace : White to grey, yellow

TP : Translucent to transparent
IR : 1.592 to 1.675
Biréfringence : 0.030
Optical character : Biaxial +
Pleochroism : Low
Fluorescence : Yellow to orange

Solubility : Sulfuric and hydrochloric acid

Magnetism : Paramagnetic
Radioactivity : None