[1913 Webster] Microcline forms during slow cooling of orthoclase; it is more stable at lower temperatures than orthoclase. The amazonite variety of microcline, exhibits a fine pleochroism. Microcline (Greek - small slope) has the same chemical composition as orthoclase but is classified in the triclinic crystal system. Help on Above, Bailey S W , American Mineralogist , 54 (1969) p.1540-1545, Refinement of an intermediate microcline structure, GRapi = 200.97 (Gamma Ray American Petroleum Institute Units) It is common in granite and pegmatites. Optical Properties : Microcline s tartan plaid twinning (a combination of albite and pericline twinning) is its most diagnostic Its structure differs from that of orthoclase because of a different distribution of silicon and aluminum atoms in its aluminosilicate crystal framework. Microcline is one of the most common stone types found in Dwarf Fortress, showing up pretty much everywhere. It is always We wouldn’t normally circle the mineral in question on the slide. The expanded formula, which additionally covers Uvite, Liddicoatite, and Buergerite, is as follows: (Na,Ca)(Mg,Li,Al,Fe 2+,Fe 3+) 3 (Al,Mg) 6 (BO 3) 3 Si 6 O 18 (OH,O,F) 4 The formula for the Tourmaline group is very complex. Name Origin: From the Greek mikron – “little” and klinein – “to stoop.” Microcline (KAlSi 3 O 8) is an important igneous rock-forming tectosilicate mineral.It is a potassium-rich alkali feldspar. See The chemical formula of Tourmaline for more details. Home Rocks and Minerals Microcline (hand specimen) Reference URL Share . In glassmaking, alumina from feldspar improves product hardness, durability, and resistance to chemical corrosion. ? Microcline, a common feldspar mineral, one form of potassium aluminosilicate (KAlSi3O8) that occurs in igneous rock. Microcline is found at Baveno, Italy; Kragerø, Nor. Amazonite is a variety that is deep green and is suitable for carving and polishing. var html = '\n\n'; Microcline typically contains minor amounts of sodium. { alert("Sorry, the print ready feature is only available in modern browsers. Feldspar Group. Scale: 2.5 x 1.5 cm. Español Microcline exhibits a variation in symmetry. Individual specimens range from those that are triclinic (three unequal axes inclined obliquely to one another) to those that are barely distinguishable from monoclinic (three unequal axes, only one of which is inclined obliquely). Microcline (Greek - small slope) has the same chemical composition as orthoclase but is classified in the triclinic crystal system. The blue-green feldspar amazonite is the only gem variety of microcline. 9: Silikate (Germanate) F: Gerüstsilikate (Tektosilikate) ohne zeolithisches H 2 O A: Gerüstsilikate (Tektosilicates) ohne weitere [Anionen] 30:Feldspat: Alkali Lapis Clas­sifica­tion. Microcline – With a triclinic arrangement, these minerals have a mild-pink to salmon color. Physical Properties of Sunstone: Chemical Formula: Microcline: KAlSi 3 O 8 Oligoclase: (Na,Ca)Al 1-2 Si 3-2 O 8: Chemical Composition: Crystal System: Triclinic: Lustre: Vitreous Microcline is a very common rock-forming mineral. Chlorite is a general name for several minerals that are difficult to distinguish by ordinary methods. Microcline is the low-temperature form of alkali feldspar. A Potash Feldspar or K-spar. } Microcline – from Greek for little and slanted, in reference to the slight variation of the cleavage angle from 90°. Alkali feldspars have a range of chemical composition and the end members may be written as KAlSi 3 O 8 and NaAlSi 3 O 8. VIII/J.06-030. The other two are orthoclase and sanidine. { Crystalline - Coarse - Occurs as well-formed coarse sized crystals. In the earth's crust, feldspars are more abundant than all other minerals combined. Microcline can occur in several colors, including clear, white, pale yellow, pink, green or red. Common world wide occurrences. Britannica Kids Holiday Bundle! The other two are orthoclase and sanidine. It is a potassium-rich alkali feldspar. Location: Crystal Park, El Paso Co., Colorado, USA. Microcline can occur in several colors, including clear, white, pale yellow, pink, green or red. html += '\n\n\n'; In Real Life . 9.FA.30. They account for an estimated 60% of exposed rocks, as well as soils, clays, and other unconsolidated sediments, and are principal components in rock classification schemes. Can occur in several colors, including clear, white, pale yellow,,! Contain sodium as well which replaces potassium within the mica group, with the chemical formula of ( 3! One form of potassium feldspar sometimes forms in association with albite or other plagioclase feldspar in composition, not. 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