Sulphates: Crocoite
Diagnostic card.
Pb CrO 4
Singonia monoclinic
Hardness 2,5-3
Specific weight 6
Cleavage is perfect
Cracked shell
Color red
Color in powder orange
Glitter diamond
Crocoite (red lead ore), - lead chromate. Luster is bold, diamond; Shines through. Coloring bright reddish-orange (in the sunlight fades). The dash is orange. The fracture is conchoidal, uneven. It's fragile. Cleavage is clear. It forms in the oxidation zone of lead ores. Crystals (monoclinic syngony) prismatic, columnar, needle-shaped, less dense aggregates. Collectible mineral. Industrial importance does not matter. Places of manifestation: CIS (Ural), Tasmania. Philippines, Brazil.
Forms aggregates of needle crystals or prismatic, highly elongated crystals (often with shading along the elongation), sometimes octahedral and rhombohedral individuals of beautiful orange-red or bright red color. The mineral was first discovered at the Berezovskoye gold mine in 1766 and was described by mountain adviser Johann Gottlieb Lehmann. Golden-orange, to red, pointed, shining, radiating along the edges of the crystals - such were the first dessine about crocoitis.
The name crochet comes from the Greek word "crocos" which means "saffron". It reflects the color of the stone - usually orange-red.
The crystals of this mineral, which can reach 40 cm in length (on the Tasmania deposit), columnar, needle-shaped and characteristic diamond shine, dimming in sunlight.
Crocoite often forms splices and crystal druses. The mineral is rather soft, its hardness is 2; 2.5.
Diagnostic signs.
In the light, the crocoid loses its shine and turns pale. Light-melting and soluble in strong acids.
Origin.
This mineral is just as rare as it is beautiful. It is formed in the oxidation zone of some lead deposits, especially those located among ultrabasic igneous rocks enriched in chromium. Occurs in the zone of weathering of sulfide deposits together with vokelenite, pyromorphite, etc.
Place of Birth.
Crocoite finds were recorded in the Berezovskoye field (in the Urals); Dundas on the island of Tasmania (from here come beautiful crystals - prisms up to 15 cm long); Goiabeira, Minas Gerais in Brazil; Nontron in France; Mammoth Cave in Arizona and Inyo County in California (USA). Crocoite has no independent industrial application and is a satellite of lead ores, but due to its rarity and beauty is considered a valuable collector's mineral.
Crocoite. Adelaide district, Dundas, Tasmania, Australia. Sample: Tucson-show-2007. Photo: © А.А. Evseev.
Krokoit is the first new mineral discovered in Russia. Berezovsky deposit, Wed.Ural. Photo: © А.А. Evseev.
Crocoite. Berezovskoye deposit, Cf. Ural, Russia, the CIS. More than 12 cm. Photo: © А.А. Evseev.
Crocoite. Berezovskoye deposit, Cf. Ural, Russia. Crystals up to 4 cm. In the background - malachite (Wed Ural). Photo: © А.А. Evseev.
Crocoite. Australia.
- Ghetchellit - "New Almaden blend" - arsenide and antimony sulfide (modern sulfosol)
- Antimony is a toxic metal (semimetal) , widely used in metallurgy, medicine and engineering
- Zirconium - a rare and undiscovered metal and the most dangerous precious stone in oxide and salt
- Gold - yellow dangerous and poisonous metal of modern accurate digital and cable technologies
- Sulfur is a golden-yellow toxic substance and a sign of active volcanic activity
- Cadmium is an undisputed toxic silvery metal unknown to a wide range of people
- Lead - a toxic gray imitator of metallic silver and toxic metal blende
- Arsenic is a classic poison of medieval and modern poisoners and medicine in medicine
Poisonous and radioactive dangerous stones and minerals
** - poisonous stones and minerals (mandatory check in the chemical laboratory + explicit indication of toxicity)
** - radioactive stones and minerals (mandatory check on the standard dosimeter + ban on open sales in case of radioactivity exceeding 24 milli / g / h + additional measures of population protection)
Catalog of minerals and semi-precious stones of the world by groups
** - poisonous stones and minerals
** - radioactive stones and minerals
Comments
When commenting on, remember that the content and tone of your message can hurt the feelings of real people, show respect and tolerance to your interlocutors even if you do not share their opinion, your behavior in the conditions of freedom of expression and anonymity provided by the Internet, changes Not only virtual, but also the real world. All comments are hidden from the index, spam is controlled.