WebMoreover, the main body shows a concentric cryptocrystalline texture from the inner to the outer part of the core with slight variations in colour. The AV1 sample displays also a distinct light/dark zonation ( Figure 3 ), nevertheless it is rougher and coarser with a micro- rather than a cryptocrystalline texture, in comparison to the MB1 ...

Texture and Genesis of Polycrystalline Varieties of Diamond

WebCryptographic —intergrowth of quartz and feldspar on so fine a scale that individual minerals cannot be clearly distinguished under the microscope; a cryptocrystalline granophyric … WebChalcedony was once thought to be a fibrous variety of cryptocrystalline quartz. More recently however, it has been shown to also contain a monoclinic polymorph of quartz, known as moganite. The fraction, by … dynamic frequency vaporwave

Quartz Mineral Photos, Uses, Properties, Pictures - Geology

WebCan be either cryptocrystalline or microcrystalline. Porphyritic Texture. This texture results when magma, with crystals already formed, escape to the surface and cools, … WebA texture of certain porphyritic rocks in which the groundmass minerals (usually quartz and alkali feldspar) penetrate each other as feathery irregular intergrowths. Resembles micrographic texture, but is more … WebChert is a microcrystalline or cryptocrystalline sedimentary rock material composed of silicon dioxide (SiO 2).It occurs as nodules and concretionary masses, and less frequently as a layered deposit. It breaks with a conchoidal fracture, often producing very sharp edges. crystal trinity