How do I identify Sekaninaite?

Sekaninaite can be identified by its hardness of 7.5 on the Mohs scale, grayish-blue to bluish-violet color. Look for these key characteristics when examining specimens.

What color is Sekaninaite?

Sekaninaite typically appears in grayish-blue to bluish-violet. Color can vary depending on impurities and formation conditions.

How hard is Sekaninaite?

Sekaninaite has a hardness of 7.5 on the Mohs scale. This makes it a relatively hard mineral suitable for jewelry.

Sekaninaite

A variety of Minerals

What is Sekaninaite?

Sekaninaite ((Fe,Mg)2Al4Si5O18) is a silicate mineral, the iron-rich analogue of cordierite. It was first described in 1968 for an occurrence in Dolní Bory, Vysočina Region, Moravia, Czech Republic, and is now known also from Ireland, Japan, and Sweden. It was named after a Czech mineralogist, Josef Sekanina (1901–1986). In Brockley on Rathlin Island, Ireland sekaninaite occurs in bauxitic clay within the contact aureole of a diabase intrusive plug.

Sekaninaite Market Value Calculator

Estimate the market value of Sekaninaite using size, quality, and finish. This preview calculator is for quick context and is not a formal appraisal.

Sekaninaite Localities Map

See where Sekaninaite is found with a localities map, collecting zones, and geology context. Generate a sample map preview below.

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North ZoneCentral RidgeSouth Basin

Key Characteristics

Characteristics of Sekaninaite

Stanek and Miskovsky (1975) first identified and diagnosed sekaninaite as a new mineral in the cordierite series. They sampled the poorly developed crystals of the Dolni Bory region, Czechoslovakia, where specimen did not exceed 70 cm. Dolni Bory samples are very different from samples found in the Kuznetsk paralavas. They are very close analogues with respect to Mg/Fe ratios but vastly different a-, b- and c- parameters (Grapes, 2010). Grapes and colleagues calculated cell dimension to be a 17.230(5), b 9.835(3), c 9.314(3) A. The colour of sekaninaite is bright blue and distinctly pleochroic with X = colourless; Y = blue; Z = pale blue; absorption occurs in the sequence Y > Z > X. Sekaninaite has a hardness of 7-7.5; it cleaves imperfectly along {100} and exhibits parting on {001} (Fleischer, 1977). Majority of crystals show zonation (Fe increasing from core to rim). It common twinned on {110} and {310}, simulating hexagonal symmetry. Sekaninaite is classified under the space group Cccm; it is an orthorhombic crystal that is found in series with cordierite (Stanek, 1975).