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Jasper is an opaque rock of virtually any colour stemming from the mineral content of the original sediments or ash. Patterns arise during the consolidation process forming flow and depositional patterns in the original silica-rich sediment or volcanic ash. Hydrothermal circulation is generally thought to be required in the formation of jasper ...
Biggs jasper is a variety of the mineral jasper. It is a "picture jasper" – a jasper that exhibits particular patterns and colors – and is used as an opaque gemstone . [ 1 ] It exhibits intricate, shell- or layer-like patterns in shades of brown ranging from beige to dark brown.
Jasper-quartz pebble conglomerate found near Bruce Mines, Ontario, Canada Jasper conglomerate is an informal term for a very distinctive Paleoproterozoic quartz and jasper pebble conglomerate that occurs within the middle part of the Lorrain Formation of the Cobalt Group of the Huronian Supergroup .
Bog-wood (also spelled bogwood or bog wood), also known as abonos and, especially amongst pipe smokers, as morta, [1] is a material from trees that have been buried in peat bogs and preserved from decay by the acidic and anaerobic bog conditions, sometimes for hundreds or even thousands of years.
Jasperoid is a rare, peculiar type of metasomatic alteration and occurs in two main forms; sulfidic jasperoids and hematitic jasperoids. True jasperoids are different from jaspillite, which is a form of metamorphosed chemical sedimentary rock, and from jasper which is a chemical sediment.
Depending on the environmental conditions present at the time of their formation, concretions can be created by either concentric or pervasive growth. [11] [12] In concentric growth, the concretion grows as successive layers of mineral precipitate around a central core. This process results in roughly spherical concretions that grow with time.
Sandstone that becomes depleted of its cement binder through weathering gradually becomes friable and unstable. This process can be somewhat reversed by the application of tetraethyl orthosilicate (Si(OC 2 H 5) 4) which will deposit amorphous silicon dioxide between the sand grains. [21] The reaction is as follows.
Chalcedony has a waxy luster, and may be semitransparent or translucent. It can assume a wide range of colors, but those most commonly seen are white to gray, grayish-blue or a shade of brown ranging from pale to nearly black. The color of chalcedony sold commercially is often enhanced by dyeing or heating. [4]