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  2. Amethyst - Wikipedia

    en.wikipedia.org/wiki/Amethyst

    Amethyst. Amethyst is a violet variety of quartz. The name comes from the Koine Greek αμέθυστος amethystos from α- a-, "not" and μεθύσκω ( Ancient Greek) methysko / μεθώ metho ( Modern Greek ), "intoxicate", a reference to the belief that the stone protected its owner from drunkenness. [ 1]

  3. Purpurite - Wikipedia

    en.wikipedia.org/wiki/Purpurite

    Purpurite. Purpurite is a manganese phosphate mineral with the formula MnPO 4, with varying amounts of iron depending upon its source. It occurs in color ranges from brownish black via purple and violet to dark red. [3] Purpurite forms a series with the iron-bearing endmember heterosite, FePO 4. [4]

  4. List of minerals - Wikipedia

    en.wikipedia.org/wiki/List_of_minerals

    This is a list of minerals which have Wikipedia articles. Minerals are distinguished by various chemical and physical properties. Differences in chemical composition and crystal structure distinguish the various species. Within a mineral species there may be variation in physical properties or minor amounts of impurities that are recognized by ...

  5. Fluorite - Wikipedia

    en.wikipedia.org/wiki/Fluorite

    Fluorite (also called fluorspar) is the mineral form of calcium fluoride, CaF 2. It belongs to the halide minerals. It crystallizes in isometric cubic habit, although octahedral and more complex isometric forms are not uncommon. The Mohs scale of mineral hardness, based on scratch hardness comparison, defines value 4 as fluorite.

  6. Sugilite - Wikipedia

    en.wikipedia.org/wiki/Sugilite

    Sugilite. Sugilite ( / ˈsuːɡəlaɪt, - dʒi -/ SOO-gə-lyte, -⁠jee-) [2] [3] is a relatively rare pink to purple cyclosilicate mineral with the complex chemical formula K Na 2 ( Fe, Mn, Al) 2 Li 3 Si 12 O 30. Sugilite crystallizes in the hexagonal system with prismatic crystals. The crystals are rarely found and the form is usually massive.

  7. Apatite - Wikipedia

    en.wikipedia.org/wiki/Apatite

    Apatite is a group of phosphate minerals, usually hydroxyapatite, fluorapatite and chlorapatite, with high concentrations of OH −, F − and Cl − ion, respectively, in the crystal. The formula of the admixture of the three most common endmembers is written as Ca 10 ( PO 4) 6 (OH,F,Cl) 2, and the crystal unit cell formulae of the individual ...

  8. Lepidolite - Wikipedia

    en.wikipedia.org/wiki/Lepidolite

    Lepidolite is a phyllosilicate mineral [ 5] and a member of the polylithionite-trilithionite series. [ 6] Lepidolite is part of a three-part series consisting of polylithionite, lepidolite, and trilithionite. All three minerals share similar properties and are caused because of varying ratios of lithium and aluminum in their chemical formulas.

  9. Ochre - Wikipedia

    en.wikipedia.org/wiki/Ochre

    Ochre is a family of earth pigments, which includes yellow ochre, red ochre, purple ochre, sienna, and umber. The major ingredient of all the ochres is iron (III) oxide-hydroxide, known as limonite, which gives them a yellow colour. A range of other minerals may also be included in the mixture: [ 5]: 134. Yellow ochre ( Goldochre) pigment.