[phosphate rock deps.] Doelter, C. () Handbuch der Mineral-chemie Seula mine (ex Montecatini quarry). [MinRec ]. Different Municipalities. Although it is still () regarded as a valid mineral species for historical reasons, opal is not a true mineral in the accepted sense of the word as it is. suomalaista DEPS-seulaa. • EPDS-seulaa (Edinburgh Postnatal Dep- ression Scale) tapauksia [14]. Positiivinen seula ei vielä merkitse depressiodiagnoosia.

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Log In Register Language: Learning Center What is a mineral? The most common minerals on earth Information for Educators Mindat Articles.

Opal This page kindly sponsored by Hobart M. Photos of Opal seu,a Opal Gallery Search Photos of Opal. Hide all sections Show all sections.

Apatite: Mineral information, data and localities.

This section is currently hidden. Click the show button to view. Colourless, white, yellow, red, orange, green, brown, black, blue. The origin of the name is uncertain. It may be des the Sanskrit “upala”, meaning “stone” or “precious stone” or from opalus, the ancient Latin name for the gem Pliny the elder, Pliny may have also referred to the gem as paederos, but a modern commentary by Kostov questions if that name was actually applied to the opal of modern sense.

Opal is classified into four types: Studies at low temperature show depe water molecules way be organized into ice-like structure, which includes the cubic ice modification Eckert et al. Nickel-Strunz 10th pending ed.: The microcrystalline varieties show birefringence: HOSi – search for seulaa with similar chemistry.

Opalus Achates unguium colore oculus mundi. Alumocalcite A variety of Opal with alumina and lime impurities. Amatite Opal formed of thick mounds deposited from hot silica-rich springs.

Amber Opal A yellow-brownish variety of Opal, resembling Amber. Andean Opal A greenish-blue opal from Peru. Andenopal German name for pink opal variety from Peru Catamarca? Bandfire Opal A precious opal with bands showing a play of colours. Black Opal The most precious kind of opalthis variety of precious opal has a dark background colour. Blue Opal Translucent blue opal with no play of colours.

Cause of colour can be light scattering effects or occasionally microscopic admixture of chrysocolla or other sejla. Cat’s Eye Opal A rare chatoyant form of opal showing a thin line of fire.

Cherry Opal A variety of common or precious opal distinguished by its red-brown color. Chrysopal Green nickeloan variety of Opal transitive to Chrysoprase Chrysopal of Schumann A translucent variety of common opal colored apple green by the presence of nickel. Claro Opal Transparent drps Precious Opal with an intense play of colours red, green, blue and yellow. Common Opal A type of opal that doesn’t show any fire. Contra Luz Opal A precious opal where the play of colours is only visible when held up to the light.


Crystal Opal A transparent to translucent variety of Precious Opal where the colour play is visible both on the surface and in the interior. Fire Opal A red variety of Opal.

Forcherite A yellow seulla orange variety of opal, owing its seupa to microscopic inclusions of orpiment and realgar. Girasol A bluish-white translucent opal with reddish reflections. Name dates back to at least Compare with Girasol Quartz which is named after this material. Gold Opal A name for yellow or gold-coloured opal Harlequin Opal A variety of Precious Opal in which the play of color is arranged in a vivid harlequin, diamond-shaped, or rectangular-shaped pattern. Honey Opal An unnecessary name for orange-brown opal.

Hungarian Opal An old name applied to any opal from Europe. Now even more mistakenly used as a name for white opal.

Hyalite A colourless variety of Opal. Because it has a different structure, it does not show the opalescence play of color that is found in precious opal.

Hyalite occurs as globular Hydrophane A variety of opal that turns translucent or transparent when immersed in water.

Jelly Opal A transparent dels with a gelatinous appearance and a bluish sheen. Lechosos Opal A variety with a milky-white background depz. Lemon Opal Another unnecessary name for a colour variety of Opal. Levin Opal Precious Opal with long thin lightning-like flashes. Lluvisnando opal A pale yellow opal Mascareignite A form of opaline silica, from a vegetable origin.

Primarily siliceous remains of grasses and diatoms. Mexican Fire Opal A transparent red opal from Mexico.

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Milk Opal A white Opal. Moss Opal Opal with dendritic inclusions, usually green silicates. Mother of Opal A sandstone or ironstone with Opal as a cement. Mountain Opal Unnecessary name for Opal from an igneous origin. Opal Matrix A term for a thin layer of opal on a host rock.

Opal-AG A type of Opal consisting of aggregated spheres of amorphous silica, with water filling the gaps in between. Precious Opal and Potch Opal consist of this kind of structure – the difference being in the regularity of the sehla of the spheres and packing. Opal-Agate A variety of Opal showing agate-like coloured bands. Opal-Jasper A variety of yellow jasper-coloured Opal. Opaline Pseudomorphs of Opal after Serpentine.


Opal: Mineral information, data and localities.

Originally described from Quicksilver region, Napa Co. Painter Boulder Sandstone boulders with a thin coating of opal. Pipe Opal Opal filling long cylindrical cavities. Precious Fire Opal Fire Opal displaying a play of colour.

Precious Opal A seulq gem-variety of opal. Most precious opal is opal-AG. It shows a play of colours “opalescence” that is due to diffraction of light from the regular packing of submicroscopic silica spheres of roughly equal size Jones et al, ; Sanders, Pyrophane Opal where colour play appears to wander about at random.

Quinzite Dpes Rose to pink Opal.

Radiolite Opal A smoky-brown opal coloured by inclusions of radiolaria exoskeletons. Red Flash Opal Precious Opal with red colour flashes that appear and disappear as the stone is turned.

Resin Opal A yellow-brown common opal with a resinous luster. Shell Opal Opal replacing fossil shells. Wax Opal A yellow-to brown opal with a waxy lustre. White Opal Precious Opal with a white background. Wood Opal Opal that has replaced fossil wood. Yowah Nut Small rounded pebbles of sandstone impregnated with Precious Opal. Originally reported from Yowah opal field, Queensland, Australia.

Associated Minerals Based on Photo Data:. Chalcedony 30 photos of Opal associated with Chalcedony on mindat. Quartz 28 photos of Opal associated with Quartz on mindat. Calcite 21 photos of Opal associated with Calcite on mindat. Topaz 15 photos of Opal associated with Topaz on mindat. Goethite 13 photos of Opal associated with Goethite on mindat. Cinnabar 12 photos of Opal associated with Cinnabar on mindat. Phillipsite 11 photos of Opal associated with Phillipsite on mindat.

Magnesite 11 photos of Opal associated with Magnesite on mindat. Fluorite 10 photos of Opal associated with Fluorite on mindat.

Ikaite 10 photos of Opal associated with Ikaite on mindat. Carbon Dioxide Ice CO 2 4. No information on health risks for this material has been entered into the database. You should always treat mineral specimens with care. An essential component of rock names highlighted in redan accessory component in rock names highlighted in green.

I Nomenclature and constituent phases.