potassium feldspar


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potassium feldspar

[pə′tas·ē·əm ′fel‚spär]
(mineralogy)
Any alkali feldspar (orthoclase, microcline, sonidine, adularia) containing the molecule KAlSi3O8. Incorrectly known as K feldspar; potash feldspar.
References in periodicals archive ?
Unlike at Petit Anse, however, at Alderney Point the unconformity is between arkosic sandstone of the upper part of the Glenkeen Formation, overlain by angular boulder conglomerate of the Horton Group containing abundant clasts of the Glenkeen sandstone, both containing potassium feldspar.
The sandstone is composed dominantly of sub-angular to semioval monomineral quartz grains, with less frequent grains of quartzite, granitic rocks, and kaolinite potassium feldspars.
6-2 mm in size correspond to oligoclase, potassium feldspar is less prevalent.
The sample is a red to pink felsic tuff that is characteristic of the unit, and is composed of about 15% 1 to 2 mm-size clear quartz and minor potassium feldspar and plagioclase crystals in a completely recrystallized quartzo-feldspathic matrix.
Imerys now imports potassium feldspar from Spain as G-200 EU, which will match the original G-200's potassium levels.
Quartz and often potassium feldspar survives the weathering and remains as part of the resultant rock.
Varying colours and surface textures were obtained by using the glass waste originated in Eskisehir, instead of ulexite, sodium feldspar and potassium feldspar (by using glass waste in equivalent amounts of the prescribed quantities of raw materials) in the alkaline and boron added standard stoneware glazes.
Product Overview II-3 Feldspar: A Common Silicate II-3 General Chemical Formula II-3 Na-Feldspars are Widely Used II-3 Physical Properties II-4 Grades II-4 Glass Grade II-4 Ceramic Body Grade II-4 Glaze Grade II-4 Types II-5 Potassium Feldspar Group II-5 Plagioclase Feldspar Group II-5 Other Feldspars II-5 Rare Feldspars II-5 Characteristics of Major Feldspar Minerals II-6 Albite (moonstone) II-6 Oligoclase Feldspar II-6 Anorthite II-7 Microcline II-7 Orthoclase II-8 History II-8 Feldspars as Gemstones II-8 Principal Stones in Feldspar Group II-9 Labradorite II-9 Moonstone II-9 Sunstone II-9 Amazonite II-9 Orthoclase II-10 Occurrence II-10 Ores and Production Process II-10 Places of Origin II-10 Production II-11
Seabridge's geologists note that hydrothermal alteration encountered in Icefields is different from other more copper rich-zones on the property, including more distinct silica alteration and more abundant potassium feldspar.
Adularia is a potassium feldspar which is found in hydrothermal systems and is often associated with very high gold-silver values.
Alteration in the area of these zones is clearly indicative of the uppermost portions of a porphyry system and includes a central core of widespread potassic alteration (biotite, potassium feldspar, and quartz-magnetite veining), quartz veining and stockwork in porphyry and surrounding sediments, a halo of disseminated pyrite, and an outer zone of propylitic alteration (chlorite, pyrite, epidote).

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