Native gold

The basic composition is Gold ( Au chemical element).

Native gold is a natural solid solution of silver (up to 43%) in gold. Impurities: Fe, Cu, Mn, Pb, less commonly Bi, Sb, Hg, Te, Se, Pt, and others ^[2] .

Syngonia is cubic. Glitter is bright, metallic. Hardness 2.5-3. Density 15.6–19.2 g / cm³ . The color is pale yellow, red-yellow, greenish.

The shape of the crystals is an octahedron , dodecahedron or cube . Fine crystals are distinguished (up to 10 microns ), dusty ( 5-50 microns ), small ( 0.05-2 mm ). In most gold deposits, particles of 0.01-4 mm prevail . It occurs in the form of doubles , as well as rectangular, dendritic , branched, leafy or spongy aggregates .

Confined to hydrothermal veins with quartz and pyrite . Present in pegmatites , black sands, alluvial deposits. The most complete formations weighing more than 1-5 g are called nuggets . The largest of them - the Holterman Plate from Australia - weighed 93.3 kg ^[3] .

In nature there are:

• Bismuth gold (up to 4% Ві );
• Pure gold ( gives birth , contains up to 43% Rh);
• Palladium gold ( porpecite );
• Gold “in a shirt” (native gold from an alluvial deposit, the surface is covered with a layer of brown iron ore );
• Mustard gold (secondary fine crystalline, as well as dense and brittle brown gold, the color of dry mustard);
• Sponge gold (native gold in the form of sponge formations);
• Green gold (green electrum from the Balei , Transbaikalia deposits);
• Gold iridic (contains up to 30.4% Ir );
• Braid gold (fine-leaved, well-polished alluvial gold found on river braids );
• Copper gold (contains up to 20% Cu );
• Gold platinum;
• Placer gold (gold found in placers);
• Gold mercury (contains up to 16.5% Hg);
• Native gold;
• Gold silver ( electrum );
• Concentrated gold (native gold mined from placer deposits and purified from mechanical impurities) ^[3] .

Incorrect usage, outdated synonyms of other minerals and gold in figurative senses:

• "Gold of Fools" ( pyrite );
• “Cat's Gold” (weathered biotite in the form of brownish-green spots);
• Bismuth gold (mineral maldonite );
• "Gold is paradoxical" (the medieval name of tellurium );
• Written gold (the same as graphic, sylvanite ), = graphic gold ( sylvanite , the placement of crystals resembles written signs);
• Antimony gold (the aurostibite mineral is an intermetallic compound of gold and antimony of the island structure, AuSb ₂ , Au - 44.74%; Sb - 55.26%);
• Steady gold (gold "in a shirt");
• Black gold (obsolete name maldonite);
• Floating gold (thin-sheet gold, which is held on the surface of the water);

• Gold Mineral Data . Mineralogy Database . webmineral.com . Date of treatment January 2, 2012. Archived November 23, 2012.