What is "pyrargyrite"

Red \Red\, a. [Compar. Redder (-d?r); superl. Reddest.] [OE. red, reed, AS. re['a]d, re['o]d; akin to OS. r[=o]d, OFries. r[=a]d, D. rood, G. roht, rot, OHG. r[=o]t, Dan. & Sw. r["o]d, Icel. rau[eth]r, rj[=o][eth]r, Goth. r['a]uds, W. rhudd, Armor. ruz, Ir. & Gael. ruadh, L. ruber, rufus, Gr. 'eryqro`s, Skr. rudhira, rohita; cf. L. rutilus. [root]113. Cf. Erysipelas, Rouge, Rubric, Ruby, Ruddy, Russet, Rust.] Of the color of blood, or of a tint resembling that color; of the hue of that part of the rainbow, or of the solar spectrum, which is furthest from the violet part. ``Fresh flowers, white and reede.'' --Chaucer. Your color, I warrant you, is as red as any rose. --Shak. Note: Red is a general term, including many different shades or hues, as scarlet, crimson, vermilion, orange red, and the like. Note: Red is often used in the formation of self-explaining compounds; as, red-breasted, red-cheeked, red-faced, red-haired, red-headed, red-skinned, red-tailed, red-topped, red-whiskered, red-coasted. Red admiral (Zo["o]l.), a beautiful butterfly ( Vanessa Atalanta) common in both Europe and America. The front wings are crossed by a broad orange red band. The larva feeds on nettles. Called also Atalanta butterfly, and nettle butterfly. Red ant. (Zo["o]l.)

1. A very small ant ( Myrmica molesta) which often infests houses.

2. A larger reddish ant ( Formica sanguinea), native of Europe and America. It is one of the slave-making species. Red antimony (Min.), kermesite. See Kermes mineral (b), under Kermes. Red ash (Bot.), an American tree ( Fraxinus pubescens), smaller than the white ash, and less valuable for timber. --Cray. Red bass. (Zo["o]l.) See Redfish (d) . Red bay (Bot.), a tree ( Persea Caroliniensis) having the heartwood red, found in swamps in the Southern United States. Red beard (Zo["o]l.), a bright red sponge ( Microciona prolifera), common on oyster shells and stones. [Local, U.S.] Red birch (Bot.), a species of birch ( Betula nigra) having reddish brown bark, and compact, light-colored wood. --Gray. Red blindness. (Med.) See Daltonism. Red book, a book containing the names of all the persons in the service of the state. [Eng.] Red book of the Exchequer, an ancient record in which are registered the names of all that held lands per baroniam in the time of Henry II. --Brande & C. Red brass, an alloy containing eight parts of copper and three of zinc. Red bug. (Zo["o]l.)

   1. A very small mite which in Florida attacks man, and produces great irritation by its bites.

   2. A red hemipterous insect of the genus Pyrrhocoris, especially the European species ( Pyrrhocoris apterus), which is bright scarlet and lives in clusters on tree trunks.

3. See Cotton stainder, under Cotton. Red cedar. (Bot.) An evergreen North American tree ( Juniperus Virginiana) having a fragrant red-colored heartwood. (b) A tree of India and Australia ( Cedrela Toona) having fragrant reddish wood; -- called also toon tree in India. Red chalk. See under Chalk. Red copper (Min.), red oxide of copper; cuprite. Red coral (Zo["o]l.), the precious coral ( Corallium rubrum). See Illusts. of Coral and Gorgonlacea. Red cross. The cross of St. George, the national emblem of the English. (b) The Geneva cross. See Geneva convention, and Geneva cross, under Geneva. Red currant. (Bot.) See Currant. Red deer. (Zo["o]l.)

   1. The common stag ( Cervus elaphus), native of the forests of the temperate parts of Europe and Asia. It is very similar to the American elk, or wapiti.

   2. The Virginia deer. See Deer. Red duck (Zo["o]l.), a European reddish brown duck ( Fuligula nyroca); -- called also ferruginous duck. Red ebony. (Bot.) See Grenadillo. Red empress (Zo["o]l.), a butterfly. See Tortoise shell. Red fir (Bot.), a coniferous tree ( Pseudotsuga Douglasii) found from British Columbia to Texas, and highly valued for its durable timber. The name is sometimes given to other coniferous trees, as the Norway spruce and the American Abies magnifica and Abies nobilis. Red fire. (Pyrotech.) See Blue fire, under Fire. Red flag. See under Flag. Red fox (Zo["o]l.), the common American fox ( Vulpes fulvus), which is usually reddish in color. Red grouse (Zo["o]l.), the Scotch grouse, or ptarmigan. See under Ptarmigan. Red gum, or Red gum-tree (Bot.), a name given to eight Australian species of Eucalyptus ( Eucalyptus amygdalina, resinifera, etc.) which yield a reddish gum resin. See Eucalyptus. Red hand (Her.), a left hand appaum['e], fingers erect, borne on an escutcheon, being the mark of a baronet of the United Kingdom of Great Britain and Ireland; -- called also Badge of Ulster. Red herring, the common herring dried and smoked. Red horse. (Zo["o]l.)

      1. Any large American red fresh-water sucker, especially Moxostoma macrolepidotum and allied species.

      2. See the Note under Drumfish. Red lead. (Chem) See under Lead, and Minium. Red-lead ore. (Min.) Same as Crocoite. Red liquor (Dyeing), a solution consisting essentially of aluminium acetate, used as a mordant in the fixation of dyestuffs on vegetable fiber; -- so called because used originally for red dyestuffs. Called also red mordant. Red maggot (Zo["o]l.), the larva of the wheat midge. Red manganese. (Min.) Same as Rhodochrosite. Red man, one of the American Indians; -- so called from his color. Red maple (Bot.), a species of maple ( Acer rubrum). See Maple. Red mite. (Zo["o]l.) See Red spider, below. Red mulberry (Bot.), an American mulberry of a dark purple color ( Morus rubra). Red mullet (Zo["o]l.), the surmullet. See Mullet. Red ocher (Min.), a soft earthy variety of hematite, of a reddish color. Red perch (Zo["o]l.), the rosefish. Red phosphorus. (Chem.) See under Phosphorus. Red pine (Bot.), an American species of pine ( Pinus resinosa); -- so named from its reddish bark. Red precipitate. See under Precipitate. Red Republican (European Politics), originally, one who maintained extreme republican doctrines in France, -- because a red liberty cap was the badge of the party; an extreme radical in social reform. [Cant] Red ribbon, the ribbon of the Order of the Bath in England. Red sanders. (Bot.) See Sanders. Red sandstone. (Geol.) See under Sandstone. Red scale (Zo["o]l.), a scale insect ( Aspidiotus aurantii) very injurious to the orange tree in California and Australia. Red silver (Min.), an ore of silver, of a ruby-red or reddish black color. It includes proustite, or light red silver, and pyrargyrite, or dark red silver. Red snapper (Zo["o]l.), a large fish ( Lutjanus aya syn. Lutjanus Blackfordii) abundant in the Gulf of Mexico and about the Florida reefs. Red snow, snow colored by a mocroscopic unicellular alga ( Protococcus nivalis) which produces large patches of scarlet on the snows of arctic or mountainous regions. Red softening (Med.) a form of cerebral softening in which the affected parts are red, -- a condition due either to infarction or inflammation. Red spider (Zo["o]l.), a very small web-spinning mite ( Tetranychus telarius) which infests, and often destroys, plants of various kinds, especially those cultivated in houses and conservatories. It feeds mostly on the under side of the leaves, and causes them to turn yellow and die. The adult insects are usually pale red. Called also red mite. Red squirrel (Zo["o]l.), the chickaree. Red tape,

         1. the tape used in public offices for tying up documents, etc. Hence,

         2. official formality and delay; excessive bureaucratic paperwork.

            Red underwing (Zo["o]l.), any species of noctuid moths belonging to Catacola and allied genera. The numerous species are mostly large and handsomely colored. The under wings are commonly banded with bright red or orange.

            Red water, a disease in cattle, so called from an appearance like blood in the urine.

n. (context mineralogy English) Ruby silver; dark red or black-coloured silver ore with a metallic adamantine luster, a sulphide of antimony and silver, Ag₃SbS₃, occurring in rhombohedral crystals

Pyrargyrite is a sulfosalt mineral consisting of silver sulfantimonide, AgSbS. Known also as dark red silver ore or ruby silver, it is an important source of the metal.

It is closely allied to, and isomorphous with, the corresponding sulfarsenide known as proustite or light red silver ore. Ruby silver or red silver ore (German Rotgiiltigerz) was mentioned by Georg Agricola in 1546, but the two species so closely resemble one another that they were not completely distinguished until chemical analyses of both were made.

Both crystallize in the ditrigonal pyramidal (hemimorphic-hemihedral) class of the rhombohedral system, possessing the same degree of symmetry as tourmaline. Crystals are perfectly developed and are usually prismatic in habit; they are frequently attached at one end, the hemimorphic character being then evident by the fact that the oblique striations on the prism faces are directed towards one end only of the crystal. Twinning according to several laws is not uncommon. The hexagonal prisms of pyrargyrite are usually terminated by a low hexagonal pyramid or by a drusy basal plane.

The color of pyrargyrite is usually greyish-black and the lustre metallic-adamantine; large crystals are opaque, but small ones and thin splinters are deep ruby-red by transmitted light, hence the name, from the Greek pyr and argyros, "fire-silver" in allusion to color and silver content, given by E. F. Glocker in 1831. The streak is purplish-red, thus differing markedly from the scarlet streak of proustite and affording a ready means of distinguishing the two minerals. The Mohs hardness is 2.75, and the specific gravity 5.85. The refractive indices (nω=3.084 nε=2.881) and birefringence (δ=0.203) are very high. There is no very distinct cleavage and the fracture is conchoidal. The mineral occurs in metalliferous veins with calcite, argentiferous galena, native silver, native arsenic, &c. The best crystallized specimens are from Sankt Andreasberg in the Harz, Freiberg in Saxony, and Guanajuato in Mexico. It is not uncommon in many silver mines in the United States, but rarely as distinct crystals; and it has been found in some Cornish mines. Although the red silver ores afford a good example of isomorphism, they rarely form mixtures; pyrargyrite rarely contains as much as 3% of arsenic replacing antimony, and the same is true of antimony in proustite. Dimorphous with pyrargyrite and proustite respectively are the rare monoclinic species pyrostilpnite or fireblende (AgSbS) and xanthoconite (AgAsS): these four minerals thus form an isodimorphous group.