The difference between gold and pyrite: 🔥 ● Gold - Crystals form as cubes or octahedrons but are rare. The usual habits are grains, flakes, nuggets and dendritic masses. Bright yellow color is tarnish resistant. Gold is often rich in silver, when it is paler in color. The band is golden yellow. GoldRead more
The difference between gold and pyrite: 🔥
● Gold – Crystals form as cubes or octahedrons but are rare. The usual habits are grains, flakes, nuggets and dendritic masses. Bright yellow color is tarnish resistant. Gold is often rich in silver, when it is paler in color. The band is golden yellow. Gold is opaque and its luster is metallic.
Formation:
Forms mainly in hydrothermal veins, often associated with quartz and sulphides. It also occurs in placer deposits of unconsolidated sand and in sandstone and conglomerate. It is possible to find alluvial gold in the form of grains or nuggets in stream beds. Gold panning by sieving sediments is an age-old method of searching for this rare and precious mineral. Gold can be confused with pyrite and chalcopyrite at first, but only a few tests are needed to identify it.
TESTS Insoluble in all simple acids; soluble in aqua regia.
Group: NATIVE ELEMENTS
Composition: Gold
Hardness: 2½–3
GS: 7:30 p.m.
Cleavage: None
● Pyrite – This mineral occurs as cubic, pyritohedral or octahedral crystals; pairing is common.
The crystal faces are frequently striated. Pyrite can be massive, granular, reniform, stalactitic, botryoidal and nodular. The pale yellow color gives rise to its nickname, “fool’s gold”. It has a greenish-black stripe. Pyrite is opaque and has a metallic luster.
Formation:
Pyrite is a common accessory mineral in igneous, sedimentary, and metamorphic rocks.
TESTS Gives off sparks on impact with a hard metal object. Fuses quite easily.
Group: SULPHIDES
Composition: FeS₂
Hardness: 6–6½
OS: 5.00–5.03
Cleavage: Indistinct
Fracture: conchoidal to uneven
Dolerite can be magnetic because it commonly contains magnetite, which is a naturally occurring mineral with magnetic properties. Magnetite is often present in small amounts in dolerite and can contribute to its magnetic properties. However, not all dolerite is necessarily magnetic, as the amount ofRead more
Dolerite can be magnetic because it commonly contains magnetite, which is a naturally occurring mineral with magnetic properties. Magnetite is often present in small amounts in dolerite and can contribute to its magnetic properties. However, not all dolerite is necessarily magnetic, as the amount of magnetite present can vary from one rock sample to another. The degree of magnetism in dolerite can also depend on the concentration, size, and distribution of magnetite grains within the rock.
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