Webis plagioclase series. twinning from Ca plagioclase to Na. and near of twinning mechanismn (L17) Twinning F12 Plagioklas. ... (monoclinic) transforms to low temperature microcline … WebUnlike plagioclase feldspars, ... Microcline is a triclinic K-feldspar and has a characteristic cross-hatched tartan pattern of twinning seen with a petrographic microscope. Orthoclase and sanidine are both optically monoclinic K-feldspars. Sanidine occurs in volcanic and subvolcanic rocks.
Thin Section Petrology Databank - Minerals & Other Inclusions ...
WebApr 1, 2024 · Quartz grains are large and equant, but grain boundaries are bulging rather than straight. Carlsbad growth twinning is preserved in plagioclase feldspar, and tartan twinning is preserved in alkali feldspar. The lack of a well-developed SPO in these samples suggests that solid-state overprinting was minimal. WebTartan Twinning. Tartan Twinning is the main diagnostic feature of microcline. It's only observed in cross polarized light and is seen as a criss-cross pattern.The twinning is a … the bad wrap software
Tartan Twinning - IMP - Google Sites
WebFeb 1, 2024 · K-feldspar megacrysts have simple twinning and tartan twinning and contain zonally arranged microlite inclusions of plagioclase, quatze, amphibole and biotite (Fig. 3 a-d). The groundmass of the monzogranites is medium to coarse grained (1–8 mm) and consists of quartz (25–30 vol%), plagioclase (25–35 vol%), K-feldspar (10–15 vol%), … WebSep 1, 2024 · The sample consists of K-feldspar porphyrocrysts, quartz, plagioclase and biotite. Partially recrystallized K-feldspar (Or 91-95 Ab 5-9 An 0) porphyrocrysts display tartan twinning characteristic of microcline and exsolved lamellae and irregular intergrowths of albite (perthite; Fig. 5 a). WebIrregularly shaped exsolution blebs of plagioclase. Microcline. Can show tartan twinning Cleavage at 90 Low negative relief. Antiperthite. When the plagioclase dominates in an … the green inferno screencaps