Sandstone Sand"stone`, n. A rock made of sand more or less firmly united. Common or siliceous sandstone consists mainly of quartz sand. Note: Different names are applied to the various kinds of sandstone according to their composition; as, granitic, argillaceous, micaceous, etc. Flexible sandstone (Min.), the finer-grained variety of itacolumite, which on account of the scales of mica in the lamination is quite flexible. Red sandstone, a name given to two extensive series of British rocks in which red sandstones predominate, one below, and the other above, the coal measures. These were formerly known as the Old and the New Red Sandstone respectively, and the former name is still retained for the group preceding the Coal and referred to the Devonian age, but the term New Red Sandstone is now little used, some of the strata being regarded as Permian and the remained as Triassic. See the Chart of Geology., Red horse. (Zo["o]l.) (a) Any large American red fresh-water sucker, especially Moxostoma macrolepidotum and allied species. (b) 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 (Lutlanus aya or 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, the tape used in public offices for tying up documents, etc.; hence, official formality and delay.