Mica on Quartz from Portugal
Size-
7.1cm x 6.1cm x 2.1cm
Weight-
143g
You will receive the item in the photo
Quartz:
Quartz is the second most abundant mineral in the continental crust and consists entirely of silicon dioxide.
Crystal system- Trigonal (low temperature) High temperature quartz is hexagonal. It commonly displays a habit of six-sided hexagonal prisms terminating in pyramids.
Mineral class- Silicates (specifically Tectosilicate)
Rock formation:
Quartz is highly resistant to weathering and found universally across all three major rock families,
Igneous- It crystallizes last from cooling silica-rich magmas,filling the voids in intrusive rock like granite and magmatic pegmatites.
Sedimentary- It forms the primary component of weathered sandstones,siltstones and chert.
Metamorphic- It creates quartzites through the recrystallisation of sandstone and is heavily present in schists and gneisses.
Mica:
Mica is a broad group of 37 chemically distinct silicate minerals,most famously known for their perfect basal cleavage that allows them to split into incredibly thin flexible sheets.
Crystal system- monoclinic
Mineral class- silicates ( specifically phyllosilicate
Rock formation: mica is highly petrogenetically significant and serves as a major rock-forming component across various geological environments.
Igneous- it crystallizes early to mid stage in intrusive igneous environments,creating massive distinct crystalline layers or books within felsic pegmatites.
Metamorphic- it is the defining mineral behind the flaky,aligned texture seen in rocks like mica schist,gneiss,phyllite and slate.
Sedimentary- Tiny reflective flakes can occasionally survive erosion to settle within clastic rocks like sandstones and shales.
