Unreferenced date March 2007 Cryptocrystalline is a rock geology rock Texture crystalline texture made up of such minute crystal s that its crystalline nature is only vaguely revealed even microscopically in thin section by transmitted polarized light . Among the sedimentary rock s, chert and flint are cryptocrystalline. carbonado diamond Carbonado , a form of diamond, is also cryptocrystalline. Volcanic rocks, especially of the acid ic type such as felsite s and rhyolite s, may have a cryptocrystalline matrix geology groundmass as distinguished from pure obsidian acidic or tachylyte basic , which are natural rock glass es. Onyx is also a cryptocrystalline. See also List of rock textures Rock microstructure Chalcedony Agate Microcrystalline Nanocrystalline Macrocrystalline Category Crystals Category Petrology Category Lithics Petrology stub no Kryptokrystallinsk fi Piilokiteisyys pl Struktura skrytokrystaliczna ... more details
Opaline may refer to Opaline , a group of protists Opaline album Opaline , an album by Dishwalla Opaline glass , the decorative French glass Opal Opaline silica an amorphous or cryptocrystalline form of hydrated silica SiO sub 2 sub n H sub 2 sub O Opal Opaline budgerigar mutation Opaline , a colour Opaline budgerigar mutation mutation of the budgerigar, Melopsittacus undulatus disambig ... more details
unreferenced date May 2010 Orphan date February 2009 In geology, macrocrystalline Rock geology rocks have crystals large enough to easily be identified by sight. Macrocrystalline or phaneritic texture is common in intrusive igneous rock s which cooled slowly enough for crystal growth. Pegmatite s are noted for very large crystal size. Rocks with crystals requiring microscopic or X ray crystallography X ray analysis for identification are termed microcrystalline or cryptocrystalline . petrology stub Category Mineralogy Category Petrology ... more details
About the mineral the fictional character Trolls Discworld Chrysoprase Trolls Discworld Image Chryzopraz 2.jpg thumb Chrysoprase Chrysoprase , chrysophrase or chysoprasus is a gemstone variety of chalcedony a cryptocrystalline form of silica that contains small quantities of nickel . Its color is normally apple green, but varies to deep green. The darker varieties of chrysoprase are also referred to as prase . However, the term prase is also used to describe Chlorite group chlorite included quartz, and to a certain extent is a color descriptor, rather than a rigorously defined mineral variety. Chrysoprase is cryptocrystalline, which means that it is composed of crystals so fine that they cannot be seen as distinct particles under normal magnification. This sets it apart from rock crystal, amethyst , citrine , and the other varieties of crystalline quartz which are basically transparent and formed from easily recognized six sided crystals. Other members of the cryptocrystalline silica family include agate , carnelian , and onyx . Unlike many non transparent silica minerals, it is the color of chrysoprase, rather than any pattern of markings, that makes it desirable. The word chrysoprase comes from the Greek language Greek chrysos meaning gold and prasinon , meaning green . Unlike emerald which owes its green color to the presence of chromium , the color of chrysoprase is due to trace amounts of nickel compounds in form of very small inclusions. The nickel reportedly occurs as different silicates, like kerolite or pimelite not NiO mineral, bunsenite, as was reported before . Chrysoprase results from the deep weathering or laterite lateritization of nickeliferous serpentinite s or other ultramafic ophiolite rocks. In the Australian deposits, chrysoprase occurs as veins and nodules with brown goethite and other iron oxide s in the magnesite rich saprolite below an iron and silica cap. As with all forms of chalcedony , chrysoprase has a hardness of 6 7 on ... more details
For other uses of Riverstone , see Riverstone . The Patuxent River stone is the state gem of the U.S. state of Maryland . It is an agate , a cryptocrystalline form of quartz . It is only found in Maryland and its red and yellow colors reflect the Maryland State Flag . The Patuxent River stone became the state gem effective October 1, 2004 through the passage of Chapter 272, Acts of 2004 Code State Government Article, sec. 13 319. ref cite web title Patuxent River Stone, Maryland State Gem work publisher Maryland State Archives date February 28, 2005 url http www.msa.md.gov msa mdmanual 01glance symbols html gem.html doi accessdate 2007 11 30 ref References reflist Category Symbols of Maryland Maryland stub ... more details
Millosevichite is a rare mineral with the chemical formula Al sub 2 sub SO sub 4 sub sub 3 sub . ref http www.mindat.org min 2713.html Mindat ref Aluminium is often substituted by iron . It forms white to yellowish cryptocrystalline , often porous, masses. The mineral is mainly known from burning coal dumps, acting as one of the main minerals forming sulfate crust . It can be also found in Volcano volcanic environments. ref Chesnokov B. V. and Shcherbakova E. P. 1991 Mineralogiya gorelykh otvalov Chelyabinskogo ugolnogo basseina opyt mineralogii tekhnogenesa. Nauka, Moscow ref ref http www.handbookofmineralogy.org Handbook of Mineralogy ref References references http webmineral.com data Millosevichite.shtml Webmineral Category Sulfate minerals sulfate mineral stub it Millosevichite ... more details
H lleflinta a Swedish language Swedish word meaning rock flint , a white, grey, yellow, greenish or pink, fine grained rock consisting of an intimate mixture of quartz and feldspar . Many examples are banded or striated others contain porphyritic crystals of quartz which resemble those of the felsites and porphyries. Mica , iron oxide s, apatite , zircon , epidote and hornblende may also be present in small amount. The more micaceous varieties form transitions to granulite and gneiss . H lleflinta under the microscope is very finely crystalline , or even cryptocrystalline , resembling the felsitic matrix of many acid rocks. It is essentially metamorphic and occurs with gneisses, schists and granulites, especially in the Scandinavia n peninsula, where it is regarded as being very characteristic of certain horizons. Of its original nature there is some doubt, but its chemical composition and the occasional presence of porphyritic crystals indicate that it has affinities to the fine grained acid intrusive rocks. In this group there may also have been placed metamorphosed acid tuffs and a certain number of adinoles shales, contact altered by intrusions of diabase . The assemblage is not a perfectly homogeneous one but includes both igneous and sedimentary rocks, but the former preponderate. Rocks very similar to the typical Swedish h lleflintas occur in German Tyrol Tirol , in Galicia Central Europe Galicia and eastern Bohemia . Category Sedimentary rocks 1911 nn Helleflint ... more details
Godovikovite is a rare mineral of the chemical formula NH sub 4 sub Al SO sub 4 sub sub 2 sub . Al can partially be substituted by Fe. Hydratation of godovikovite gives the ammonium alum, tschermigite . The mineral forms cryptocrystalline, often porous, masses, usually of white colour. Single crystals are very small hexagonal blades. Typical environment for godovikovite are burning coal sites mainly dumps . There the mineral acts, together with millosevichite , as one of the main components of so called sulfate crust. ref Chesnokov B. V. and Shcherbakova E. P. 1991 Mineralogiya gorelykh otvalov Chelyabinskogo ugolnogo basseina opyt mineralogii tekhnogenesa. Nauka, Moscow ref ref Jambor J. L. and Grew E. S. 1990 New mineral names. American Mineralogist, 76, pp. 240 246 ref References references http webmineral.com data Godovikovite.shtml Webmineral http www.mindat.org min 1717.html Mindat Category Sulfate minerals sulfate mineral stub it Godovikovite ... more details
The term tool stone has multiple meanings. In archaeology , a tool stone is a type of stone that is used to manufacture stone tool s. ref name Lithics cite book first William last Andrefsky Jr. title Lithics Macroscopic Approaches to Analysis publisher Cambridge University Press year 2005 edition Second Edition isbn 0521615003 ref Alternately, the term can be used to refer to stones used as the raw material for tools. ref name Folsom cite book isbn 9781879621275 url http books.google.ca books?id 8oUIAQAAMAAJ&q 22tool stone 22&dq 22tool stone 22&hl en&ei 7LKoTIn4H4mDnQedjqGkDQ&sa X&oi book result&ct result&resnum 5&ved 0CEQQ6AEwBA title Folsom lithic technology explorations in structure and variation publisher International Monographs in Prehistory author Daniel S. Amick date 1999 page accessdate 2010 10 03 quote ref Generally speaking, tools that require a sharp edge are made using cryptocrystal line materials that fracture in an easily controlled Conchoidal fracture conchoidal manner. ref name Lithics Cryptocrystalline tool stones include flint and chert , which are fine grained sedimentary materials rhyolite and felsite , which are igneous flowstone s and obsidian , a form of natural glass created by igneous processes. These materials fracture in a predictable fashion, and are easily resharpened. For more information on this subject, see lithic reduction . Large grained materials, such as basalt , granite , and sandstone , may also be used as tool stones, but for a very different purpose they are ideal for ground stone Artifact archaeology artifacts . Whereas cryptocrystalline materials are most useful for killing and processing animals, large grained materials are usually used for processing plant matter. Their rough faces often make excellent surfaces for grinding plant seeds. With much effort, some large grained stones may be ground down into stitching awl awls , adzes , and axes . In the contemporary diamond industry a tool stone is a diamond attached to a pol ... more details
Infobox mineral name Heliotrope category boxwidth boxbgcolor image Quarz Heliotrop Blutjaspis .JPG imagesize 200 caption A heliotrope, also known as a bloodstone. formula Silicon Si Oxygen O sub 2 sub silicon dioxide molweight color habit system Trigonal twinning cleavage fracture tenacity mohs 6.5 7 luster Vitreous lustre Vitreous polish refractive 1.53 1.54 opticalprop birefringence 0.004 dispersion pleochroism fluorescence absorption streak gravity 2.61 density melt fusibility diagnostic solubility diaphaneity other references The mineral heliotrope , also known as bloodstone , is a form of chalcedony which is a cryptocrystalline mixture of quartz and its monoclinic polymorphism materials science polymorph moganite . The classic bloodstone is green chalcedony with red inclusion mineral inclusion s of iron oxide or red jasper . Sometimes the inclusions are yellow, in which case the mineral is given the name plasma . The red inclusions are supposed to resemble spots of blood hence the name bloodstone . The name heliotrope from Greek helios , Sun, trepein , to turn derives from various ancient notions about the manner in which the mineral reflects light. These are described, e.g., by Pliny the Elder Natural History Pliny Nat. Hist. 37.165 . Heliotrope is the traditional birthstone for March. Sources The primary source of the stone is India . It is also found in Brazil , China , Australia and the United States . There is also an outcrop of Bloodstone on the R m Isle Of Rum , in Scotland . References Hall, Candy A. 1994 . Gem Stones . DK Publishing. ISBN 1 56458 498 4. Silica minerals DEFAULTSORT Heliotrope Mineral Category Quartz varieties de Heliotrop Mineral fr H liotrope min ral he nl Heliotroop mineraal ja pl Heliotrop minera pt Heliotropo ru sv Heliotrop mineral ... more details
. Results have been promising, but not spectacular. Obsidian and cryptocrystalline silicates appear ... the major advantage of relying on obsidian flaking as the activating cause in this dating scheme. Cryptocrystalline ... more details
The Gunflint chert 1.88 Annum Ga ref cite journal title The age of the Gunflint Formation, Ontario, Canada single zircon U Pb age determinations author Fralick, P., David, D. W. and Kissin, Stephen A. journal Canadian Journal of Earth Sciences volume 39 issue 7 pages 1085 1091 year 2002 doi 10.1139 E02 028 ref is a sequence of banded iron formation rocks that are exposed in the Gunflint Range of northern Minnesota and northwestern Ontario along the north shore of Lake Superior . The black layers in the sequence contain microfossil s that are 1.9 to 2.3 billion years in age. Stromatolite colony biology coloni es of cyanobacteria that have been converted to jasper are found in Ontario. The banded ironstone formation consists of alternating stratum strata of iron oxide rich layers interbedded with silica rich zones. The iron oxides are typically hematite or magnetite with ilmenite , while the silicates are predominantly cryptocrystalline quartz as chert or jasper , along with some minor silicate minerals. Stanley A. Tyler examined the area in 1953, and noted the red colored stromatolites. He also sampled a jet black chert layer which, when observed petrographic ally, revealed some life like small spheres, rods and filaments less than 10 micrometres in size. Elso Barghoorn , a paleobotanist at Harvard , subsequently looked at these same samples. Barghoorn concluded that they were indeed structurally preserved unicellular microbe organism s. ref Past lives Chronicles of Canadian Paleontology http gsc.nrcan.gc.ca paleochron 05 e.php ref In 1965, the two scientists published their finding, and named a variety of the Gunflint flora . ref Barghoorn, E.S. and Tyler, S.A., 1965 Microorganisms from the Gunflint Chert . Science, vol. 147, p. 563 577. ref This created an academic stampede to explore Precambrian microfossil s from similar Proterozoic environments. See also Oxygen catastrophe References references Schopf, J.W., 1999 Cradle of Life The Discovery of Earth s Earliest ... more details
Infobox mineral name Papagoite category Silicate mineral boxwidth boxbgcolor image Papagoite k 152b.jpg caption Crystalline papagoite from Namibia size 5.9 x 3.3 x 2.1 cm formula CaCuAlSi sub 2 sub O sub 6 sub OH sub 3 sub symmetry Monoclinic 2 m unit cell a 12.92 , b 11.49 , c 4.69 100.81 Z 4 color Dark blue crystals, light blue when massive habit Massive cryptocrystalline, forming flat elongated crystals system Monoclinic prismatic twinning cleavage Imperfect in one direction fracture Brittle mohs 5 5.5 luster Vitreous to dull refractive n sub sub 1.607 n sub sub 1.641 n sub sub 1.672 opticalprop Biaxial birefringence 0.065 2V Measured 78 pleochroism Trichroic streak Light blue gravity 3.25 melt fusibility diagnostic solubility diaphaneity other references ref name Mindar http www.mindat.org min 3077.html MinDAT ref ref name Webmin http webmineral.com data Papagoite.shtml Webmineral ref ref name HBM http rruff.geo.arizona.edu doclib hom papagoite.pdf Handbook of Mineralogy ref Papagoite is a rare Silicate mineral Cyslosilicates cyclosilicate mineral . Chemically, it is a calcium copper aluminium silicate hydroxide , found as a secondary mineral on slip surfaces and in altered granodiorite veins, either in massive form or as microscopic crystals that may form spherical aggregates. Its chemical formula is Calcium Ca Copper Cu Aluminium Al Silicon Si sub 2 sub Oxygen O sub 6 sub Oxygen O Hydrogen H sub 3 sub . File Copper Papagoite Quartz tmu46b.jpg thumb left Papagoite and native copper on a quartz crystal from Limpopo Province , South Africa size 7.0 x 3.7 x 2.6 cm It was discovered in 1960 in Ajo, Arizona , USA , and was named after the Hia C ed O odham Sand Papago peoples now named Hia C ed O odham that inhabit the area. ref name HBM This location is the only papagoite source within the United States , while worldwide it is also found in South Africa and Namibia . It is associated with aurichalcite , shattuckite , ajoite and baryte in Arizona, and w ... more details
and chert are the most commonly knapped materials and are compact cryptocrystalline quartz . The difference ... be used to describe the family of cryptocrystalline quartz es that are suitable for knapping. As well as cryptocrystalline quartz , macrocrystalline quartz both vein quartz and rock crystal was a commonly ... more details
, cryptocrystalline and microfibrous quartz. The term does not include quartzite . Chalcedony ... Banded Iron Formation specimen from Upper Michigan showing red chert layers. The cryptocrystalline ... more details
Infobox mineral name Datolite category Silicate mineral image Datolite rom25c.jpg caption Datolite on sphalerite from San Luis Potos , Mexico size 6.2 x 5.3 x 2.8 cm formula CaBSiO sub 4 sub OH strunz dana symmetry Monoclinic prismatic 2 m unit cell a 9.62 , b 7.6 , c 4.84 90.15 Z 4 molweight color Colorless or white may be grayish, yellow, green, red, pink colour habit Crystal prismatic, short to tabular Botryoidal or globular with columnar structure granular to compact cryptocrystalline system Monoclinic twinning cleavage fracture Conchoidal to uneven tenacity Brittle mohs 5 to 5.5 luster Vitreous, rarely subresinous on fracture surface streak diaphaneity Transparent to translucent, rarely opaque gravity 2.96 3.00 density polish opticalprop Biaxial refractive n sub sub 1.626 n sub sub 1.653 1.654 n sub sub 1.670 birefringence 0.044 pleochroism 2V Measured 74 dispersion r v weak extinction length fast slow fluorescence Fluoresces blue under SW UV absorption melt fusibility diagnostic solubility impurities alteration other references ref name HBM http rruff.geo.arizona.edu doclib hom datolite.pdf Handbook of Mineralogy ref ref name Mindat http www.mindat.org min 1340.html Mindat ref ref name Webmin http webmineral.com data Datolite.shtml Webmineral ref Datolite is a calcium boron hydroxide Silicate minerals nesosilicate , calcium Ca boron B silicon Si oxygen O sub 4 sub O hydrogen H . It was first observed by Jens Esmark in 1806, and named by him from , to divide, and , stone, in allusion to the granular structure of the massive mineral. ref Wikisource1911Enc Citation Datolite ref Datolite crystallizes in the monoclinic system forming prismatic crystal s and nodular masses. The luster is vitreous and may be brown, yellow, light green or colorless. The Mohs hardness is 5.5 and the specific gravity is 2.8 3.0. File Datolite 132458.jpg thumb left Polished datolite nodule from the Quincy Mine of Michigan s Copper Country size 4.1 x 3.3 x 1.7 ... more details
streeter1 Geochemistry Structure Chalcedony was once thought to be a fibrous variety of cryptocrystalline ... cryptocrystalline , and so has a very high surface area to volume ratio. Citation needed date February ... more details
Infobox mineral name Magnesite category Carbonate mineral boxwidth boxbgcolor image Mineraly.sk magnezit.jpg caption formula MgCO sub 3 sub molweight strunz 05.AB.05 color Colorless, white, pale yellow, pale brown, faintly pink, lilac rose habit Usually massive, rarely as rhombohedrons or hexagonal prisms system Trigonal Hexagonal Scalenohedral H M Symbol overline 3 2 m Space Group R overline 3 c twinning cleavage 10 overline 1 1 perfect fracture Conchoidal tenacity Brittle mohs 3.5 4.5 luster Vitreous refractive n sub sub 1.508 1.510 n sub sub 1.700 opticalprop Uniaxial birefringence pleochroism streak white gravity 3.0 3.2 melt fusibility infusible diagnostic solubility Effervesces in hot HCl diaphaneity Transparent to translucent other May exhibit pale green to pale blue fluorescence and phosphorescence under UV triboluminescent references ref name Handbook http rruff.geo.arizona.edu doclib hom magnesite.pdf Handbook of Mineralogy ref ref name Mindat http www.mindat.org min 2482.html Mindat.org ref ref name Webmin http webmineral.com data Magnesite.shtml Webmineral data ref ref name Klein Klein, Cornelis and Cornelius S. Hurlbut, Jr., Manual of Mineralogy, Wiley, 20th ed., p. 332 ISBN 0 471 80580 7 ref Magnesite is magnesium carbonate , magnesium Mg carbon C oxygen O sub 3 sub . Iron as iron Fe sup 2 sup substitutes for magnesium Mg with a complete solution series with siderite , FeCO sub 3 sub . Calcium , manganese , cobalt , and nickel may also occur in small amounts. Dolomite , Mg, calcium Ca CO sub 3 sub , is almost indistinguishable from magnesite. Occurrence Magnesite occurs as veins in and an alteration product of ultramafic rocks , serpentinite and other magnesium rich rock types in both contact and regional metamorphic rock metamorphic terranes. These magnesites often are cryptocrystalline and contain silica as opal or chert . Magnesite is also present within the regolith above ultramafic rocks as a secondary carbonate within soil and subsoil, where ... more details
Image Novaculite Flatirons Marathon Uplift.JPG thumb right 240px Novaculite Flatiron geomorphology flatirons in the Marathon Uplift ref cite book first1 Darwin V. last1 Spearing title Roadside Geology of Texas publisher Mountain Press Publishing Company isbn 087842265X year 1991 ref Novaculite is a form of chert or flint found in the Ouachita Mountains of Arkansas and Oklahoma and in the Marathon Uplift of Texas . Novaculite is considered to be highly siliceous sediments and may be a product of the low grade metamorphism of chert beds. The stratum strata were deposited in the Devonian Period and subjected to uplift and folding during the Ouachita orogeny of the Pennsylvanian Permian Periods. Novaculite is very resistant to erosion and the layers of novaculite stand out as ridges in the Ouachita Mountains. Novaculite is a form of microcrystalline or cryptocrystalline quartz . The color varies from white to grey black and the specific gravity shows an increase from 2.2 to 2.5. The very hard dense rock is used as a sharpening stone whetstone . It has been mined since prehistoric times both as material for use as arrow and spear points and as sharpening stones. Moreover, the upper strata of Arkansas Novaculite, known as Rotten stone tripoli , has found a niche within the coatings, adhesives, sealants and elastomer industry as a performance additive or filler. Tripoli is mined just east of Hot Springs, Arkansas by Malvern Minerals Company. ref http www.fs.fed.us r8 ouachita natural resources minerals otherminerals.shtml Nichols, John C., Minerals on the Ouachita National Forest, USDA Forest Service 12 May 2008 ref The word novaculite is derived from the Latin word novacula , for razor stone. References Folk, R.L., and E.F. McBride, 1976, The Caballos Novaculite revisited Part I origin of novaculite members . Journal of Sedimentary Petrology. 46 659 669 Folk, R.L., and E.F. McBride, 1978, Origin of the Caballos Novaculite . in S.J. Mazzullo, ed., Tectonics and Paleozoic f ... more details
The Lig rian is a regional Geology geological stage geology substage of the Turonian . It designates sediment s of the Lower Turonian in western France . Etymology The name Lig rian, in French language French Lig rien , is derived from the Latin Ligera , which stands for the Loire River. Occurrence The Lig rian is encountered in the Touraine southwestern part of the Paris Basin near Saumur along the River Loire, type locality of the Turonian. But it can equally be found in the northern Aquitaine Basin . Stratigraphy The Lig rian, abbreviated as c3a on French geological map s, is the lowest substage of the Turonian. It overlies the Cenomanian and is in turn overlain by the Angoumian . In the northern Aquitaine Basin the Lig rian, also known as the Villars Formation , shows the following stratigraphy stratigraphy At its base the Lig rian consists of an alternating succession of nearly meter sized limestone beds and very thin intervening grey marl y horizons. The limestone is white and very chalk y. At the contact with the underlying Cenomanian it is detritic and contains coarse quartz grains, small sized gravels and the fragments of ground up lamellibranch s and echinoderm s. Higher up in the section the marly layers gradually disappear and the rock takes on a massive, homogeneous and cryptocrystalline aspect thickness 5 to 10 meters . Stratification within the Lig rian, if recognisable, is nodular, wavy to platy. The rock disintegrates to short, prismatic columns. Because of its erodibility and incompetent nature the Lig rian forms slopes beneath the much more resistant Angoumian cliffs. Farmers grow cereals on its easily workable layers. Compared to other Cretaceous Upper Cretaceous rocks the Lig rian is rather poor in fossil content. Its fauna consists mainly of lamellibranchs like arca noueliana , cardium productum , exogyra columba oyster and inoceramus labiatus , of gasteropod s pleurotomaria galliennei , of hexacoral s and of bryozoa , towards the top annelid s ... more details
, rudist bearing, cryptocrystalline limestones . Texturally they are wackestone s grading into mudstone ... clastic dominated members formed, whereas in the calm inner lagoon, the cryptocrystalline and micritic ... more details
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