Kerolite

• Kerolite
• Cerolit
• Hydrosilicit
• Talk shell

Cerolite is still primarily viewed as a nickel-containing variety of talc. He is since 1979 because of doubts about its specific independence not as a separate mineral. In the literature it is also described as a mineral mixture of serpentine and saponite (soap stone) from the mineral class of silicates. Kerolithe occur preferentially in dense, greasy -feeling, tough, amorphous masses.

Special Features

Cerolite aggregates subject to natural aging, coupled with a green discoloration of the original mineral. It goes back to a release of water in a hot environment and under the influence of sunlight. Aged, dehydrated Kerolithe are white to gray waxy yellow and opaque. The aging process - and thus the discoloration - can be stopped in ( mountain ) humid environment and reversed to a certain extent.

With regard to the examination of the hygroscopic properties described in 1823 August Breithaupt the cerolite as a substance that does not depend on the tongue, in order to underline the special position of the mineral in the studied group of him the opal-like minerals talc.

However, when out stinging diagnostic feature he defined the oily, greasy to waxy feel. In the laboratory test the blowpipe - cerolite soda mixture showed when blowing in the oxidation flame a bright red color, which traced Breithaupt slight amount of lithium in the sample.

Etymology and history

The cerolite was described by Breithaupt in 1823 for the first time from a sample from the area of Frankenstein in Silesia. Due to its characteristic soapy, sometimes a little greasy to waxy feel Breithaupt described him as a guard stone (Greek κηρός, wax ', λίθος ' stone ' ).

Around the same time described the mineral as Otto cow Hydrosilicit. This name is therefore often cited in the literature as a synonym. Since cerolite occurs mainly intergrown, additive or incorporation into other minerals, its specific independence is controversial today.

Education and Locations

Cerolite formed during the decomposition or chemical weathering magnesium and nickel- ultrabasic rocks. In the best-studied deposit Gläsendorf cerolite occurs together with Pimelit (Ni- saponite ) and Stevensite (Mn - saponite ) in a network of thin fractures in the transition zone between highly altered and less decomposed ultrabasic rocks on.

Cerolite was described by Breithaupt in various localities in Saxony in the serpentinite of Zöblitz as platy aggregates, in Hartmann village, in the amygdaloid of Upper mockery village as well as from various basalts of Bohemia and Saxony ( Stolpen and Hauenstein ). Important sites of cerolite lie further in Poland in the district of Frankenstein ( Frankenstein, Gläsendorf, exhausted ), in England (Cornwall, St Keverne ), the Urals ( Elov mine in Yekaterinburg, near Magnitogorsk, Svetly and Orsk in Orenburg ), in the U.S., including in Hawaii ( Kauai ), Maine ( Thomaston, Union, and Warren ), Nevada ( Nye County), North Carolina ( Macon County, Madison County) and Masscchusetts ( Essex County). In addition, there are still deposits in New Caledonia ( Yaté ), Italy ( in Balangero ), Sweden ( Dalarna ) and in East Cameroon.

Use as a gemstone

The intense apple green color of chrysoprase, a chalcedony variety is due to a finely divided admixture of cerolite. However, the high sensitivity of the Keroliths to heat and desiccation limits its processing as a gemstone.

The presence of cerolite intense green colored Chrysoprase were looking for gemstones especially in the past. Were the famous made ​​from this material, plenty of wall panels and table tops from Ząbkowice Śląskie ( Frankenstein, Silesia) that made Frederick the Great customize for Sanssouci Palace. Also decorated with numerous Chrysoprasplatten the walls of the St. Wenceslas Chapel at St. Vitus Cathedral. In some European regalia, including the crown of the Norwegian Queen, cerolite Chrysoprase are processed.