Serandite - Encyclopedia

    Class : Silicates
    Subclass : Inosilicates
    Crystal System : Triclinic
    Chemistry : Na(Mn, Ca)2Si3O8(OH)
    Rarity : Rare

Serandite forms an isomorphic series with pectolite, its calcic equivalent, the intermediate terms being called schizolite. It owes its name to the mineral collector J. M. Sérand, who participated in its collection on the island of Rouma in Guinea. Serandite is essentially a mineral of alkaline complexes, it crystallizes in the geodes of nepheline syenites and their pegmatites. It occurs in thick prismatic or tabular crystals, of a beautiful pale pink to salmon pink or red, sometimes pinkish gray color. It is sometimes cut but its rarity and its fairly low hardness do not allow it to rise to the rank of jewelry stone, it is more reserved for the collection. Its crystals are also sought after by mineral collectors.

Serandite in the World

Extraordinary associations composed of 25 cm salmon pink crystals, decimetric prisms of aegyrine and isometric crystals of analcime, were discovered in the open quarries of the alkaline syenites of Mont Saint-Hilaire (Canada) : these are of the finest crystals in the world. These quarries also produced less spectacular, pinkish gray crystals of 5 cm. The nepheline syenites of the Los Islands (Guinea) yielded the first serandite crystals, elongated pink-colored individuals. Serandite is also known from other localities, including the Gem Mine benitoite deposit (San Benito, California, USA) and the Points of Rocks phonolite geodes (New Mexico).

Serandite in France

This mineral is not present in the French underground.


This mineral twins around the composition plane [010], the contact twin is less frequent on (110).

Fakes ans treatments

No fake identified for this mineral species.

Hardness : 5 to 5,5
Density : 3.34
Fracture : Uneven

Streak : White

TP : Translucent to transparent
IR : 1.668 to 1.703
Birefringence : 0.035
Optical character : Biaxial +
Pleochroism : None
Fluorescence : None

Solubility : Hydrochloric acid

Magnetism : None
Radioactivity : None