Dendritic agate is a whitish-gray or colorless chalcedony with tree- or fern-like markings known as dendrites. The variety name agate is used for this gem even though it does not exhibit the banding typical of agate.

Dendritic Agate Rough

The dendrites in dendritic agate are iron or manganese inclusions, usually brown or black in color. Though they appear organic due to their fern-like structure, they are actually inorganic; they are formed at fine fracture surfaces through crystallization of weathered solutions of neighboring rock.

Dendritic agate can be tricky to cut because the dendrite inclusions occur at various depths in the rough stone. The lapidary needs to cut the material to expose the most interesting patterns.

The famous Russian jeweler Carl Faberge, who was a supplier to the Russian Imperial Court from 1885 to 1916, used dendritic agates together with diamonds and other precious stones for many of his pieces. Dendritic agate is prized in Russia as a stone of long life, good health and prosperity.

Like other chalcedonys, dendritic agate has a hardness of 6.5 to 7 on the Mohs scale, a specific gravity of 2.59-2.67 and a refractive index of 1.530-1.540. Since chalcedony has no cleavage it is quite durable and can be used for all sorts of jewelry.

Dendritic Agate Cabochon

Because of its dendritic inclusions, dendritic agate bears some similarities to moss opal. But dendritic agate is not called moss agate. In fact there is a another gemstone called moss agate, which has inclusions of green hornblende in moss-like patterns.

Dendritic agate deposits are found in Brazil, India, Madagascar, the USA, Mexico and Khazakstan.

Dendritic Agate is believed to aid in communication with nature. It is associated with the protection of the earth, rain, prosperity, abundance, healing, restoration and creativity. It said to improve self esteem and emotional balance.