Cryptocrystalline is a rock texture made up of such minute crystals that its crystalline nature is only vaguely revealed even microscopically[1] in thin section by transmitted polarized light. Among the sedimentary rocks, chert and flint are cryptocrystalline. Carbonado, a form of diamond, is also cryptocrystalline. Volcanic rocks, especially of the felsic type such as felsites and rhyolites, may have a cryptocrystalline groundmass as distinguished from pure obsidian (felsic) or tachylyte (mafic), which are natural rock glasses. Agate and onyx are examples of cryptocrystalline silica (chalcedony).
^American Geological Institute (1984). Bates, Robert Latimer; Jackson, Julia A. (eds.). Dictionary of geological terms (3rd ed.). Garden City, New York: Anchor Press/Doubleday. p. 120. ISBN 0385181000. OCLC 9412868.
Cryptocrystalline is a rock texture made up of such minute crystals that its crystalline nature is only vaguely revealed even microscopically in thin...
Flint, occasionally flintstone, is a sedimentary cryptocrystalline form of the mineral quartz, categorized as the variety of chert that occurs in chalk...
hard, fine-grained sedimentary rock composed of microcrystalline or cryptocrystalline quartz, the mineral form of silicon dioxide (SiO2). Chert is characteristically...
microcrystalline or cryptocrystalline varieties (aggregates of crystals visible only under high magnification). The cryptocrystalline varieties are either...
carbonate rock Chert – Hard, fine-grained sedimentary rock composed of cryptocrystalline silica Claystone – Clastic sedimentary rock composed primarily of...
chrysophrase or chrysoprasus is a gemstone variety of chalcedony (a cryptocrystalline form of silica) that contains small quantities of nickel. Its color...
sharp edge are made using cryptocrystalline materials that fracture in an easily controlled conchoidal manner. Cryptocrystalline tool stones include flint...
(/kælˈsɛdəni/ kal-SED-ə-nee, or /ˈkælsəˌdoʊni/ KAL-sə-doh-nee) is a cryptocrystalline form of silica, composed of very fine intergrowths of quartz and moganite...
contact and regional metamorphic terrains. These magnesites are often cryptocrystalline and contain silica in the form of opal or chert. Magnesite is also...
Trigonal or monoclinic Identification Color banded Crystal habit Cryptocrystalline silica Cleavage None Fracture Conchoidal, with very sharp edges Mohs...
Jasper, an aggregate of microgranular quartz and/or cryptocrystalline chalcedony and other mineral phases, is an opaque, impure variety of silica, usually...
of the amorphous character of a mineral, or a material. Amorphous, cryptocrystalline, and crystalline materials can all present conchoidal fracture when...
of: whether the stone is of a cryptocrystalline structure, and how conchoidally the stone fractures. A cryptocrystalline stone is one that is made up of...
like other types of agate, are composed of concentric layers of cryptocrystalline chalcedony colorized by different trace minerals. However, fortification...
Cementite (synthetic cohenite) Ceylonite (variety of spinel) Chalcedony (cryptocrystalline variety of quartz and moganite) Chiastolite (variety of andalusite)...
characteristics when it comes to creating flake tools, cryptocrystalline and conchoidal fracture. Cryptocrystalline relates to a stone structure that is made up...
fibrous crystals only a few micrometers in size or smaller are called cryptocrystalline chondrules. When the pyroxene fibers are coarser, they may appear...
minerals. These are usually quartz and clay minerals, though collophane (cryptocrystalline apatite, a phosphate mineral) is also sometimes present, as nodules...
volcanic rock. Enhydro agates are made up of banded microcrystalline or cryptocrystalline quartz. The agate has a hollow center, partially containing water...
Onyx is formed of bands of chalcedony in alternating colors. It is cryptocrystalline, consisting of fine intergrowths of the silica minerals quartz and...
dissolution and reprecipitation of interstitial minerals (often quartz or cryptocrystalline silica) by hot, hydrothermal fluids and the expansion and contraction...
microcrystalline, but the extreme range of values suggested is 1 to 200 microns. Cryptocrystalline Macrocrystalline Nanocrystalline Nanocrystalline silicon Microcrystalline...
latter fashioned by a flintknapper. Knapped stone tools are made from cryptocrystalline materials such as chert, flint, radiolarite, chalcedony, obsidian...
related to the propagation of a Hertzian cone of force through the cryptocrystalline matrix of the stone, but the particulars are poorly understood. Eraillures...
Chert – Hard, fine-grained sedimentary rock composed of cryptocrystalline silica Flint – Cryptocrystalline form of the mineral quartz Concretion – Compact mass...
stone tools are usually made of basalt, rhyolite, granite, or other cryptocrystalline and igneous stones whose coarse structure makes them ideal for grinding...
Novaculite, also called Arkansas Stone, is a microcrystalline to cryptocrystalline rock type that consists of silica in the form of chert or flint. It...
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