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The color of Amazonite is based on 3 components: lead, water and radiation..

Foto: K. Sieber, www.makrogalerie.de


Minerals are chemical substances formed by natural processes. In contrast to the artificially created, solid chemical compounds (chemicals), which are mostly produced in form of powders , the minerals that are interesting for mineral collectors and jewelry lovers are crystallized in a clearly visible size. Minerals may - just like industrial products - carry heavy metals and other elements which under certain circumstances can have a harmful effect on human health or the environment.

As long as a mineral - with the exception of radioactive minerals - is only placed on the windowsill and looked at, its ingredients can usually be ignored. The important thing is not what is inside a mineral, but what is released into the environment or absorbed by the human body.

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Eclipse / Bumblebee Stone (Calcite with arsenic sulfides)

Eclipse / Bumblebee Stone (Calcit mit Arsensulfiden)

Arsenic sulfides are not suitable for jewelry

Photo: K. Sieber, www.makrogalerie.de

We got to know this yellow-grey marbled rock under the trade name "Eclipse". Apparently, the inventor of this name was reminded of a solar eclipse when looking at the stone. First publications described it as "an aragonite sinter from Bali/Indonesia interspersed with very thin layers of sulfur and Auripigment" (NIEDERMAYER 2010). It turned out that the material originates from a fumarole field near the town of Garut on the Indonesian island of Java (SERRAS-HERMAN 2013).

The trade name "Eclipse" did not establish itself. In English-speaking areas the stone is offered as "Bumble Bee Jasper" or "Mustard Jasper".

Analyses carried out the EPI laboratory showed that this stone is by no means a jasper. Rather, it consists essentially of calcite. Tiny pyrite crystals (FeS) are embedded in the grey areas of the calcite, contributing to its dark color. In investigations of the University of Freiberg, the arsenic mineral realgar (As4S4), a compound of the elements arsenic and sulfur (arsenic sulfide), could be detected in the golden yellow to orange colored areas. The chemically closely related arsenic mineral Auripigment (As4S6) on the other hand could not be detected. This does not necessarily mean that it is not present, it merely could not be detected. In earlier publications (NIEDERMAYR, G. , 2010) it was assumed that the yellow color is brought about by Auripigment. This would be more consistent, since Auripigment has a yellow-orange color, whereas realgar is more of a red-orange color. It is possible that the yellow color is caused by the other arsenic sulfides, whose presence was indicated by the data of the University of Freiberg but which could not be specified explicitly (GÖTZE et al. 2014). Based on these findings, the preliminary mineralogical name for this rock is: REALGAR CALCITE.

Like all arsenic sulfides, realgar is toxic under certain conditions.

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In nature, solid/native mercury is mostly vergesellschaftet with cinnabar (vermilion).

Cinnabar (vermilion)


Cinnabar quartz

Photo: K. Sieber, www.makrogalerie.de

The mercury (II) sulfide cinnabar (vermilion, HgS) is the most common mercury compound on the market. Cinnabar in a pure, fresh form is insoluble in water and as a well crystallized, compact crystal unproblematic. However, the situation is very different for cinnabar dust. It can even be absorbed through the skin and is very toxic if swallowed or inhaled.

As a gemstone the mineral is usually offered in the form of cinnabar quartz or cinnabar opal. Firmly bound in quartz or opal cinnabar is harmless. Only in places where it emerges at the surface a decomposition reaction can take place and elemental mercury is produced.