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  2. Speleothem - Wikipedia

    en.wikipedia.org/wiki/Speleothem

    H 2 O + CO 2 → H 2 CO 3. As the acidic water travels through the calcium carbonate bedrock from the surface to the cave ceiling, it dissolves the bedrock via the reaction: CaCO 3 + H 2 CO 3 → Ca 2+ + 2 HCO 3 −. When the solution reaches a cave, the lower pCO 2 in the cave drives the precipitation of CaCO 3 via the reaction: Ca 2+ + 2 HCO ...

  3. Placer deposit - Wikipedia

    en.wikipedia.org/wiki/Placer_deposit

    Placer minerals are defined as having a specific gravity above 2.58. [1] The separation of the valuable minerals from the most common non-economic mineral, quartz, depends on the difference in specific gravity / density.The weathering process allows for the accumulation of placer minerals, while less dense material such as quartz are swept away.

  4. Kimberlite - Wikipedia

    en.wikipedia.org/wiki/Kimberlite

    Once collected, heavy minerals are separated and sorted by hand to identify these indicators. Chemical analysis confirms their identity and categorizes them. Techniques like thermobarometry help understand the conditions under which these minerals formed and where they came from in the Earth's mantle. By analyzing these indicators and ...

  5. Mineral - Wikipedia

    en.wikipedia.org/wiki/Mineral

    Corundum group minerals have a 2:3 ratio, and includes minerals such as corundum (Al 2 O 3), and hematite (Fe 2 O 3). Rutile group minerals have a ratio of 1:2; the eponymous species, rutile (TiO 2) is the chief ore of titanium; other examples include cassiterite (SnO 2; ore of tin), and pyrolusite (MnO 2; ore of manganese).

  6. 511 Davida - Wikipedia

    en.wikipedia.org/wiki/511_Davida

    511 Davida is a large C-type asteroid in the asteroid belt.It is one of the largest asteroids; approximately tied for 7th place, to within measurement uncertainties, and the 5th or 6th most massive.

  7. Evaporite - Wikipedia

    en.wikipedia.org/wiki/Evaporite

    Evaporite minerals, especially nitrate minerals, are economically important in Peru and Chile. Nitrate minerals are often mined for use in the production on fertilizer and explosives . Thick halite deposits are expected to become an important location for the disposal of nuclear waste because of their geologic stability, predictable engineering ...

  8. Arsenic - Wikipedia

    en.wikipedia.org/wiki/Arsenic

    Arsenic forms colorless, odorless, crystalline oxides As 2 O 3 ("white arsenic") and As 2 O 5 which are hygroscopic and readily soluble in water to form acidic solutions. Arsenic(V) acid is a weak acid and its salts, known as arsenates , [ 36 ] are a major source of arsenic contamination of groundwater in regions with high levels of naturally ...

  9. Rock (geology) - Wikipedia

    en.wikipedia.org/wiki/Rock_(geology)

    The original rock, known as the protolith, transforms into other mineral types or other forms of the same minerals, by recrystallization. [5] The temperatures and pressures required for this process are always higher than those found at the Earth's surface: temperatures greater than 150 to 200 °C and pressures greater than 1500 bars. [ 18 ]