Riebeckite is an interesting and unusual silicate mineral belonging to the alkaline amphiboles.

The mineral has a complex composition, is a hydrous silicate of magnesium, sodium, iron with the formula Na2(Mg,Fe2+)3Fe3+2×Si8O22(OH)2.

Reebeckite also contains impurities of calcium, titanium, manganese, potassium and, occasionally, lithium.


  • the crystal structure has a monoclinic system and consists of double chains of silicon-oxygen (Si4O11) tetrahedra;
  • prism-perfect cleavage;
  • crystals are formed in the form of asbestos-like, lamellar, fibrous, rod-shaped, granular aggregates, elongated prismatic and acicular habit;
  • average hardness – 5.5;
  • good density – 3.4 g/cm3;
  • the color of riebeckites can be from light blue to blue-black, black, gray, gray-blue, brown;
  • glassy, matte and silky shine;
  • the mineral can be opaque and translucent;
  • individual processed riebeckite crystals shimmer in blue, yellow-green and brown shades;
  • acid resistance;
  • fire resistance.

Types of riebeckites


is the most valuable variety of riebeckite in a beautiful blue or blue-gray color. A silicified crocidolite with a greenish-blue or blue color is called a hawk’s eye, and a yellowish-brown one is called a tiger’s eye. Both are used for jewelry and crafts.

Rhodusite (or magnesioribeckite, blue asbestos) –

divalent iron is replaced by magnesium. Differs in light and dark blue color. Like crocidolite, it occurs in quartz, forming a beautiful hawk’s eye. Rhodusite is processed into cabochon and inserted into jewelry, used for making small crafts.

Origin and deposits

The origin of riebeckites is metasomatic or igneous. The mineral is present as an accessory in alkaline syenites, granites, and sometimes in volcanics, shales, and granitic pegmatites.

Reebeckite deposits: Kazakhstan, Canada, Nigeria, South Africa, Kenya, USA. Named in honor of the German mineralogist E. Riebeck.


In addition to jewelry and ornaments, riebeckite is used:

for making paints. It was known as a pigment in Ancient Egypt. Occasionally used in icon painting. The advantages of riebeckite paints include resistance to external factors, the disadvantages are unsaturation, a certain grayish tint;

in the production of fire-fighting and heat-insulating materials.

Stones on the ground

These verses are about how stones lie on the ground,
simple stones, half of which do not see the sun,
simple gray stones,
simple stones – stones without epitaphs.

Stones that take our steps
white in the sun, and stones at night
like the large eyes of a fish,
stones that grind our steps –
eternal millstones of eternal bread.

Stones that take our steps
like black water – gray stones,
stones decorating the neck of a suicide,
precious stones polished by prudence.

Stones on which they will write: “freedom”.
Stones that will one day pave the road.
The stones from which prisons will be built
or stones that will remain motionless,
like stones that do not evoke associations.

stones lie on the ground,
simple stones resembling the back of heads,
simple stones – stones without epitaphs.


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