Zeolites: stilbene (Desmin)
Diagnostic Card.
Above: prismatic crystals stilbite. Below: in rounded nodules stilbite seen their inner radial-fibrous structure.
Ca Al 2 Si 7 O 18 * 7 H 2 O
Crystal system monoclinic
Hardness of 3.5-4
Specific weight 2,09-2,2
Cleavage is very good
Fracture irregular, brittle
Color colorless or light gray
Color white powder
Gloss glass
Usually it forms irregular crystals, often combined in a typical sheaf-like aggregates, as well as in radiating and spherulitic group. Sometimes there are individual euhedral tabular crystals grow together in cruciform twins mimicking rhombic symmetry. Painting is colorless or grayish-white. Gloss glass and mother of pearl on the cleavage planes.
Chemical composition. Volatile; approximate composition: calcium oxide (CaO) 7z9%, aluminum oxide (Al2O3) 16-18%, silicon dioxide (SiO2) 55z61%, water (H2O) 16,5-19%. Form crystals. Sheaf-like aggregates. Class symmetry. Prismatic - 2 / m. Cleavage. Perfect for (010). Aggregates. Columnar, radiant, foliated, sheaf-like, spherulitic.
Diagnostic features.
It melts in the flame of a candle, and dissolves easily in hydrochloric acid. Fused into a white enamel. Behavior in acids. Decomposes into HCl.
Origin.
In association with other zeolites usually occurs in cavities of basaltic rocks. In a lithoclase (together with quartz epidote, adularia and other minerals of hydrothermal origin) is found in metamorphic rocks.
Place of Birth.
Beautiful crystal formation stilbite basalts found in Iceland, Scotland and the Islands Fair Isle. In Italy, met in augite andesites Montresta near the town of Oristano (Sardinia), in Adamello tonalite and granite of Baveno near Lago majeure on the island of Elba.
Stilbene. Iceland. Druse split crystals. Stilbene. Detail of geodes in mandelshteyne. Small Kunaley d., Hillock p., Baikal, Russia. Photo: © AA Evseev.
Stilbene. Druse split crystals. Charinka p., Wed. Siberia, Krasnoyarsk Krai, Russia. Stilbene. NY Wales, Australia. 10x10 cm Photo:. © AA Evseev.
Kavansit, stilbene. District Pune, India. 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.