Alaskite
Intrusive igneous rock of felsic composition.
This rock sample is a large rather amorphous chunck of the mineral commonly called milky quartz. Large light colored veins cutting through older intrusive igneous and metamorphic rocks. Large crystalline masses composed of milky quartz occurs is associated with alaskite veins. Alaskite is a a “leucocratic” (meaning light colored) granite of medium or fine grain composed chiefly of quartz and alkali feldspars. Aplite is an intrusive igneous rock in which the mineral composition is the same as granite, but in which the grains are much finer, under 1 mm across.
This sample is derived from Anza Borrego desert region alluvial gravel deposit near Agua Caliente County Park, CA, downstream from the Peninsular Ranges Eastern granitic belt. |
| https://gotbooks.miracosta.edu/rocks/igneous/16.html |
2/2/2021 |
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