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Pyrite is the most common of sulfide minerals and is widespread in igneous, metamorphic, and sedimentary rocks. It is a common accessory mineral in igneous rocks, where it also occasionally occurs as larger masses arising from an immiscible sulfide phase in the original magma.
Twenty questions. Twenty questions is a spoken parlor game which encourages deductive reasoning and creativity. It originated in the United States and was played widely in the 19th century. [1] It escalated in popularity during the late 1940s, when it became the format for a successful weekly radio quiz program. [citation needed]
Jade is an umbrella term for two different types of decorative rocks used for jewelry or ornaments. Jade is often referred to by either of two different silicate mineral names: nephrite (a silicate of calcium and magnesium in the amphibole group of minerals), or jadeite (a silicate of sodium and aluminum in the pyroxene group of minerals). [1]
A block of talc. Petrologically, soapstone is composed predominantly of talc, with varying amounts of chlorite and amphiboles (typically tremolite, anthophyllite, and cummingtonite, hence its obsolete name, magnesiocummingtonite), and traces of minor iron-chromium oxides. It may be schistose or massive.
Calculus (dental) Heavy staining and calculus deposits exhibited on the lingual surface of the mandibular anterior teeth, along the gumline. Calculus deposit (indicated with a red arrow) on x-ray image. In dentistry, calculus or tartar is a form of hardened dental plaque. It is caused by precipitation of minerals from saliva and gingival ...
Turpentine (which is also called spirit of turpentine, oil of turpentine, terebenthine, terebenthene, terebinthine and, colloquially, turps) is a fluid obtained by the distillation of resin harvested from living trees, mainly pines. Principally used as a specialized solvent, it is also a source of material for organic syntheses.
Blue pigments are natural or synthetic materials, usually made from minerals and insoluble with water, used to make the blue colors in painting and other arts. The raw material of the earliest blue pigment was lapis lazuli from mines in Afghanistan, that was refined into the pigment ultramarine. Since the late 18th and 19th century, blue ...
Sheets of mica Photomicrographs of a thin section containing phlogopite. In cross-polarized light on left, plane-polarized light on right. Dark mica from eastern Ontario. Micas (/ ˈ m aɪ k ə z / MY-kəz) are a group of silicate minerals whose outstanding physical characteristic is that individual mica crystals can easily be split into extremely thin elastic plates.