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  2. Quartz - Wikipedia

    en.wikipedia.org/wiki/Quartz

    Quartz. Quartz is a hard, crystalline mineral composed of silica (silicon dioxide). The atoms are linked in a continuous framework of SiO 4 silicon–oxygen tetrahedra, with each oxygen being shared between two tetrahedra, giving an overall chemical formula of SiO 2. Quartz is, therefore, classified structurally as a framework silicate mineral ...

  3. Chalcedony - Wikipedia

    en.wikipedia.org/wiki/Chalcedony

    Chalcedony. Chalcedony (/ kælˈsɛdəni / kal-SED-ə-nee, or / ˈkælsəˌdoʊni / KAL-sə-doh-nee) [2] is a cryptocrystalline form of silica, composed of very fine intergrowths of quartz and moganite. [3] These are both silica minerals, but they differ in that quartz has a trigonal crystal structure, while moganite is monoclinic.

  4. Pneumonoultramicroscopicsilicovolcanoconiosis - Wikipedia

    en.wikipedia.org/wiki/Pneumonoultramicroscopicsi...

    Etymology. Pneumono­ultra­micro­scopic­silico­volcano­coniosis is the longest word in the English language. The word can be analysed as follows: Pneumono: from ancient Greek (πνεύμων, pneúmōn) which means lungs. ultra: from Latin, meaning beyond. micro and scopic: from ancient Greek, meaning small looking, referring to the ...

  5. Charoite - Wikipedia

    en.wikipedia.org/wiki/Charoite

    Charoite (/ tʃ æ r oʊ. aɪ t / CHAR-ow-ait) is a rare silicate mineral with the chemical composition K(Ca,Na) 2 Si 4 O 10 (OH,F)•H 2 O, first described in 1978.It is named after the Chara River, despite its being 70 kilometres (43 mi) away from the discovery place.

  6. Engineered stone - Wikipedia

    en.wikipedia.org/wiki/Engineered_stone

    Engineered stone. Engineered stone is a composite material made of crushed stone bound together by an adhesive to create a solid surface. The adhesive is most commonly polymer resin, with some newer versions using cement mix. This category includes engineered quartz (SiO 2), polymer concrete and engineered marble stone. [1]

  7. Agate - Wikipedia

    en.wikipedia.org/wiki/Agate

    Agate (/ ˈ æ ɡ ɪ t / AG-it) is a variety of chalcedony, [1] which comes in a wide variety of colors. Agates are primarily formed within volcanic and metamorphic rocks.The ornamental use of agate was common in Ancient Greece, in assorted jewelry and in the seal stones of Greek warriors, [2] while bead necklaces with pierced and polished agate date back to the 3rd millennium BCE in the Indus ...

  8. Peridot - Wikipedia

    en.wikipedia.org/wiki/Peridot

    Peridot (/ ˈpɛrɪˌdɒt, - ˌdoʊ / PERR-ih-dot, -⁠⁠doh), sometimes called chrysolite, is a yellow-green transparent variety of olivine. Peridot is one of the few gemstones that occur in only one color. Peridot can be found in mafic and ultramafic rocks occurring in lava and peridotite xenoliths of the mantle.

  9. Pegmatite - Wikipedia

    en.wikipedia.org/wiki/Pegmatite

    Pegmatite. A pegmatite is an igneous rock showing a very coarse texture, with large interlocking crystals usually greater in size than 1 cm (0.4 in) and sometimes greater than 1 meter (3 ft). Most pegmatites are composed of quartz, feldspar, and mica, having a similar silicic composition to granite.