Cordierite

Origin: Tshombe, Madagascar

Sample size: left 3.5 x 2 x 2 cm, right 3 x 2 x 2 cm

Photo courtesy of:

Tom Loomis

Dakota Matrix Minerals

Cordierite in anhydrite with chalcopyrite

Origin: Ruttan Mine , Leaf Rapids, Manitoba, Canada
ex. Ian Nicklin Collection

Sample size: 3.5 x 3.5 x 2.5 cm

Pinite" pseudomorph after cordierite. Pinite is not a valid species but is rather a mixture of other secondary species that replace certain silicate minerals, such as cordierite in particular.

Origin: Felspar, Vasterby, Ammeberg, Nark, Sweden

Sample size: 15 x 10.6 x 9.3 cm

Photo courtesy of:

Rob Lavinsky

The Arkenstone

Purple-blue grains with quartz and biotite

Origin: Reinsfjell, Dypvåg near Arendal, Norway

Sample size: 2.5 x 4 cm

Blue grains (up to 5mm) in quartz-biotite matrix

Origin: Böbrach, Bayerischer Wald, Germany

Sample size: 3 x 4.5 cm

Coarse grained Al-rich biotite granite (± tourmaline) with grey rounded to blocky grains of cordierite

Origin: Garrovillas, Spain

Sample size: small cabinet

Coarse grained quartz-cordierite segregations in biotite-anthophyllite rocks (left), coarse grained quartz-cordierite segregation with cordierite crystals up to one cm coloured brown due to pinitisation (right)

Origin: Bjordammen, Telemark, Norway

Sample size: 6 x 8 cm

A Na-Ca- and Be-rich cordierite is described from the pegmatites from Lipovka. Recorded Be-contents are up to 6% BeO (M. Murshko pers comm. 2006; normally Be in Cordierite is only present in ppm-range); massive orange in matrix
Origin: Lipovka, Central Ural, Russia

Sample size: micromount