Chlorites (silicates): Vermiculite
Diagnostic Card.
(Mg, Fe, Al) 3 (OH) 2 (Al Si) 4 O 10 * 4 H 2 O
Crystal system monoclinic
Hardness 1-2
The proportion of 2.1-2.7
Cleavage is perfect
Color colorless, green, brown
Color in light green powder
luster pearl
It crystallizes usually in the form of tiny flakes, but can also form distinct crystals pseudohexagonal-plate shape. It is soft, able to bend, is colorless, but it is yellow, green or brown; pearly luster. Brown, yellowish - brown, golden - yellow, bronze - yellow, green to blackish color.
Chemical composition. Magnesium oxide (MgO) 14 - 23% ferrous oxide (FeO) 1 - 3% iron oxide (Fe2O3) 5 - 17%, aluminum oxide (Al2O3) 10 - 13%, silicon dioxide (SiO2) 37 - 42% water (H2O) 8 - 18%. Gloss. Bold, glass (on the cleavage planes pearl). Fracture. Mineral cleaved into thin sheets, this property is frequently used.
Form crystals. Poor manifested, sometimes it's the small "packets mica" (but this is not mica in the mineralogical sense), but more often foliated aggregates; It is also characterized by pseudomorphs after biotite and phlogopite. The crystal structure. Layered. Class symmetry. Probably, prismatic - 2 / m. Cleavage. Good on the basis of (001). P. tr. Very strong swells.
Diagnostic features.
Plates vermiculite by the fast warm-up (up to about 300 o C) lose water, decaying leaves, and on the increase in volume, growing perpendicular to the cleavage plane and at the same time acquiring wormlike shape. Behavior in acids. Decomposes into HCl.
Origin.
Vermiculite - a secondary product of hydrothermal biotite transformation, often forms pseudomorphs on this mineral. Moreover, it occurs in areas of contact with acidic rocks intrusive basic. In the form of tiny flakes comes in mudstones, which is one of the main components.
Deposits and application.
Large deposits are in North Carolina and elsewhere in the United States. Large deposits are also in Western Australia, Transvaal Province (South Africa), Kenya, the provinces of Ontario and Quebec (Canada). Vermiculite - important minerals. After partially burning it gives a very light product is used as an insulating material in construction. It is also used in the manufacture of plastics, paints and paper.
Vermiculite. Buldym, Cherry Mountain, South Urals, Russia. More than 6 cm Photo:. AA Evseev.
Vermiculite vermiform. Photo: AA Evseev.
- Gatchell - "New Almadén snag" - arsenide and antimony sulfide (modern sulphosalts)
- Antimony - toxic metal (semi-metal) are widely used in industry, medicine and engineering
- Zirconium - a rare and non- metal and dangerous jewel in the oxide and salts
- Gold - yellow dangerous and toxic metal -date and accurate digital cable technology
- Sulphur - a golden-yellow toxic substance and a sign of volcanic activity
- Cadmium - a toxic uncirculated unknown wide range of people silvery metal
- Lead - a poisonous gray simulator silver metal and toxic metal snag
- Arsenic - poison classic medieval and modern poisoners and medicine in medicine
Toxic and hazardous radioactive rocks and minerals
** - Poisonous stones and minerals (obligatory check in chemical laboratory + clear indication of toxicity)
** - Radioactive rocks and minerals (obligatory check on a regular dosimeter + ban on the open sale of radioactivity in the event of more than 24 mR / hour + additional measures to protect the population)
Catalog minerals and gems in groups of the world
** - Poisonous stones and minerals
** - Radioactive rocks and minerals
Comments
Commenting, keep in mind that the content and the tone of your messages can hurt the feelings of real people, show respect and tolerance to his interlocutors, even if you do not share their opinion, your behavior in terms of freedom of speech and anonymity offered by the Internet, is changing not only virtual, but real world. All comments are hidden from the index, spam control.