Stukenberg Geology Museum of Kazan State University
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Oxides and Hydroxides

Many of the minerals are widely-spread in the earth shell. There are only 13% of quartz in particular. This class implies minerals, representing the compounds of metals or semimetals with oxygen, hydroxo-group or water. At present we know more than 150 of them. Their color is connected with admixtures of chromophore elements. Being the most important ores of many precious metals, many of them are non-metallic useful minerals.

The KSU Geology Museum has a considerable collection of oxides and hydroids. Quartz as the most widely-spread oxide is represented by all the main types. One can see amethysts from the Urals deposits, Hungary and Brazil, mountain crystals from Germany, morions and rauchtopazes from Kazakhstan and Baikal Region, as well as rose quartz from Turkistan deposits and Yakutia.

Some exhibition stalls display colorful types of chalcedony. The Museum is proud of the remarkable collection of agates from different deposits all over the world, acquired from Kranz Company in the XIX century and the collection of multi-colored chalcedonies from Verkhoyanye, gifted to the museum by A.A.Zamarayev, former graduate of the Geology Faculty.

Samples of the so-called "Venus hairstones" are worth admiring. This is the case when arrow-head crystals of other minerals such as green actinolite, red rutile and black tourmaline, are found inside quartz crystals.

Ore oxides of the exposition are chosen mainly in different deposits of the Urals. Special pride of the Mineralogy Section Display implies gigantic crystals of black spinel from Nikolaye-Maksimilianovski mines of Nazyamskiye Mountains in the Urals. Weight of one of the crystals is more than 21 kg.

Hydroxides are represented by a nice set of opal samples from different parts of the world. The museum has precious opals of quite rare beauty from Australia. The theme collection of Tikhvinskoye bauxite deposit shows aluminium hydroxides. Ferrum hydroxides are represented by collections from Kerchenskoye deposit and Lake Baikal, as well as manganese hydroxides from Nikopolskoye (Ukraine), Chiaturi (Georgia) and Ilfeld (Germany).

Quartz is found almost everywhere in the earth shell. It is characterized by both various color and very different forms of morphology. Crystal quartz can be colorless and transparent (mountain crystal), purple (amethyst), grey or smoky (rauchtopaz), yellow (citrine) or black and non-transparent (morion).

Precious types of sinter quartz (chalcedony) are determined by color in the same way. Laminated chalcedony is called agate or onyx, brown chalcedony - sard, orange - carnelian, red - carneol, light-blue - sapphirine, green chalcedony - chrysoprase and white - cacholong. Sometimes one can find red disseminations in green chalcedony. In such rare case in is called heliotrope or blood-stone.

Sometimes other green minerals, called prase or plasma, make chalcedony dirty-green of different shades. Finally, widely-spread variegated rocks, known since ancient times and used by jewelers, such as jaspers (Urals, Altai) and flints (the Volga Region and localities near Moscow), consist of quartz and chalcedony.

Goethite. The Urals
The Urals

Mountain Crystal. Madagascar Island
Mountain Crystal.
Madagascar Island

Opal. The Urals
The Urals

Spinel. Nikolaye-Maksimilianovski mines, the Urals. Weight 21 kg
Nikolaye-Maksimilianovski mines, the Urals.

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