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2. Pegmatite - Wikipedia

   en.wikipedia.org/wiki/Pegmatite

   A white border rind of fine-grained quartz-albite muscovite pegmatite. A continuous layer of very coarse quartz, albite, and muscovite. This zone also contains microcline, and has abundant accessory apatite, beryl, and tantalite. Beryl is occasionally very coarse and abundant. A continuous layer of massive quartz.

3. Vein (geology) - Wikipedia

   en.wikipedia.org/wiki/Vein_(geology)

   White veins in dark rock at Imperia, Italy. In geology, a vein is a distinct sheetlike body of crystallized minerals within a rock. Veins form when mineral constituents carried by an aqueous solution within the rock mass are deposited through precipitation. The hydraulic flow involved is usually due to hydrothermal circulation. [1]

4. Quartzite - Wikipedia

   en.wikipedia.org/wiki/Quartzite

   Quartzite can have a grainy, glassy, sandpaper-like surface. Quartzite is a hard, non-foliated metamorphic rock which was originally pure quartz sandstone. [1] [2] Sandstone is converted into quartzite through heating and pressure usually related to tectonic compression within orogenic belts.

5. Micrographic texture - Wikipedia

   en.wikipedia.org/wiki/Micrographic_texture

   This fine-grained texture is similar to the coarser intergrowths in certain pegmatites and coarse granitic veins; the quartz forms angular patches scattered through a matrix of feldspar. In polarized light the separate areas of each mineral extinguish at the same time, and this proves that, even though apparently discontinuous, they have the ...

6. Phyllic alteration - Wikipedia

   en.wikipedia.org/wiki/Phyllic_alteration

   Vein orientation is preserved from original rock, but minerals within are mostly replaced by pyrite. [3] With decreasing depth, selvages widen (10 cm - 1m) and contain more quartz and pyrite. Outside of selvages, most alteration occurs in replacement of mafic minerals by chlorite and of plagioclase by sericite.

7. List of minerals - Wikipedia

   en.wikipedia.org/wiki/List_of_minerals

   Amethyst crystals – a purple quartz Apophyllite crystals sitting right beside a cluster of peachy bowtie stilbite Aquamarine variety of beryl with tourmaline on orthoclase Arsenopyrite from Hidalgo del Parral, Chihuahua, Mexico Aurichalcite needles spraying out within a protected pocket lined by bladed calcite crystals Austinite from the Ojuela Mine, Mapimí, Durango, Mexico Ametrine ...