Can be anhedral or euhedral. Grains are commonly elongate with a tabular appearance. May contain lamellae which formed from exsolved albite.
Twinning
Typically displays albite twinning and pericline twinning. This combination leads to a grid pattern, hence microcline displays gridiron twinning. Can also display carlsbad twinning, simple twins, or lack twinning altogether. Lamellae in microcline are discontinuous and "pinch and swell".
Photomicrograph of thin section of microcline showing crosshatched crystal twinning (in cross polarized light)
Cleavage
Has perfect cleavage parallel to {001} and good cleavage on {010}. Cleavages intersect at 90°41'. It can be difficult to see cleavage in thin section due to microcline's low relief.
Gridiron twinning distinguishes microcline from other feldspars. Distinguishable from plagioclase because the lamellae in plagioclase are continuous and do not "pinch and swell."
Alters to
Commonly alters to sericite or clay.
Relief
Low negative relief
Optical sign
Biaxial negative
Color in PPL
Colorless
Microcline (KAlSi3O8) is an important igneous rock-forming tectosilicate mineral. It is a potassium-rich alkali feldspar. Microcline typically contains minor amounts of sodium. It is common in granite and pegmatites. Microcline forms during slow cooling of orthoclase; it is more stable at lower temperatures than orthoclase. Sanidine is a polymorph of alkali feldspar stable at yet higher temperature. Microcline may be clear, white, pale-yellow, brick-red, or green; it is generally characterized by cross-hatch twinning that forms as a result of the transformation of monoclinic orthoclase into triclinic microcline.
The chemical compound name is potassium aluminium silicate, and it is known as E number reference E555.
Microcline (KAlSi3O8) is an important igneous rock-forming tectosilicate mineral. It is a potassium-rich alkali feldspar. Microcline typically contains...
KAlSi3O8), an important tectosilicate mineral that forms igneous rock Microcline, chemically the same as orthoclase, but with a different crystalline structure...
Cassiterite is a tin oxide mineral, SnO2. It is generally opaque, but it is translucent in thin crystals. Its luster and multiple crystal faces produce...
largest crystals are found within pegmatites. These include crystals of microcline, quartz, mica, spodumene, beryl, and tourmaline. Some individual crystals...
Sunstone is a microcline or oligoclase feldspar, which when viewed from certain directions exhibits a spangled appearance. It has been found in Southern...
Pedial is also triclinic hemihedral. Mineral examples include plagioclase, microcline, rhodonite, turquoise, wollastonite and amblygonite, all in triclinic...
green tectosilicate mineral, a variety of the potassium feldspar called microcline. Its chemical formula is KAlSi3O8, which is polymorphic to orthoclase...
lower-temperature polymorph of KAlSi3O8 is microcline. Adularia is a low temperature form of either microcline or orthoclase originally reported from the...
mineralogy. The alkali feldspar in granites is typically orthoclase or microcline and is often perthitic. The plagioclase is typically sodium-rich oligoclase...
small comma-shaped and tubular "jades" using materials such as jade, microcline, jasper, etc., in southern Korea originates from the Middle Mumun Pottery...
River. Major minerals include plagioclase, microcline, quartz, and muscovite. Perthitic textures on the microcline are possible. Minor minerals include biotite...
potash feldspar, in others the soda feldspar predominates. Fresh clear microcline is very characteristic of some types of nepheline syenite. Sodalite, colorless...
and volcanic rock fragments with a matrix composed of angular quartz, microcline and orthoclase among other minerals.[citation needed] Both Uluṟu and Kata...
feldspar minerals for example, whose end members are albite, NaAlSi3O8 and microcline, KAlSi3O8. At high temperatures Na+ and K+ readily substitute for each...
Litchfield, Maine Llanite – Type of mineral – A hypabyssal rhyolite with microcline and blue quartz phenocrysts from the Llano Uplift in Texas Luxullianite –...
faceted and polished minerals Labradorite specimen Quartz var. agate geode Microcline specimen Quartz var. amethyst geode The David S. and Ruth L. Gottesman...
chrysoberyl) Allingite (synonym of amber) Alum Amazonite (variety of microcline) Amethyst (purple variety of quartz) Ametrine (variety of quartz) Ammolite...
NaAlSi3O8, in composition). Typically, the host grain is orthoclase or microcline, and the lamellae are albite. If sodic feldspar is the dominant phase...
granodiorite. The minerals within the rock include quartz, plagioclase feldspar, microcline, and muscovite, with smaller amounts of biotite and tourmaline. The tourmaline...
Albite often occurs as fine parallel segregations alternating with pink microcline in perthite as a result of exolution on cooling. There are two variants...
the replacement was incomplete. The illustration shows tartan-twinned microcline having completely replaced plagioclase. The places with incomplete replacement...
igneous and metamorphic rocks and veins in association with lepidolite, microcline, and spodumene in granite pegmatites; with andalusite and biotite in schist;...
is composed of two varieties of feldspar (mostly albite but also some microcline), with nepheline, sodalite, cancrinite and calcite. The mafic minerals...
minerals) may have epitaxic relations. An example is albite NaAlSi 3O 8 on microcline KAlSi 3O 8. Both these minerals are triclinic, with space group 1, and...
monoclinic polymorph stable at lower temperatures. At yet lower temperatures, microcline, a triclinic polymorph of potassium feldspar, is stable. Due to the high...
Global Information
