Py·ri·tes n.  Min. A name given to a number of metallic minerals, sulphides of iron, copper, cobalt, nickel, and tin, of a white or yellowish color.
 Note: ☞ The term was originally applied to the mineral pyrite, or iron pyrites, in allusion to its giving sparks when struck with steel.
 Arsenical pyrites, arsenopyrite.
 Auriferous pyrites. See under Auriferous.
 Capillary pyrites, millerite.
 Common pyrites, isometric iron disulphide; pyrite.
 Hair pyrites, millerite.
 Iron pyrites. See Pyrite.
 Magnetic pyrites, pyrrhotite.
 Tin pyrites, stannite.
 White iron pyrites, orthorhombic iron disulphide; marcasite.  This includes cockscomb pyrites (a variety of marcasite, named in allusion to its form), spear pyrites, etc.
 Yellow pyrites, or Copper pyrites, the sulphide of copper and iron; chalcopyrite.
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 Tin n.
 1. Chem. An elementary substance found as an oxide in the mineral cassiterite, and reduced as a soft silvery-white crystalline metal, with a tinge of yellowish-blue, and a high luster.  It is malleable at ordinary temperatures, but brittle when heated. It is softer than gold and can be beaten out into very thin strips called tinfoil. It is ductile at 2120, when it can be drawn out into wire which is not very tenacious; it melts at 4420, and at a higher temperature burns with a brilliant white light. Air and moisture act on tin very slightly. The peculiar properties of tin, especially its malleability, its brilliancy and the slowness with which it rusts make it very serviceable.  With other metals it forms valuable alloys, as bronze, gun metal, bell metal, pewter and solder.  It is not easily oxidized in the air, and is used chiefly to coat iron to protect it from rusting, in the form of tin foil with mercury to form the reflective surface of mirrors, and in solder, bronze, speculum metal, and other alloys. Its compounds are designated as stannous, or stannic. Symbol Sn (Stannum). Atomic weight 117.4.
 2. Thin plates of iron covered with tin; tin plate.
 3. Money. [Cant]
 Block tin Metal., commercial tin, cast into blocks, and partially refined, but containing small quantities of various impurities, as copper, lead, iron, arsenic, etc.; solid tin as distinguished from tin plate; -- called also bar tin.
 Butter of tin. Old Chem. See Fuming liquor of Libavius, under Fuming.
 Grain tin. Metal. See under Grain.
 Salt of tin Dyeing, stannous chloride, especially so called when used as a mordant.
 Stream tin. See under Stream.
 Tin cry Chem., the peculiar creaking noise made when a bar of tin is bent. It is produced by the grating of the crystal granules on each other.
 Tin foil, tin reduced to a thin leaf.
 Tin frame Mining, a kind of buddle used in washing tin ore.
 Tin liquor, Tin mordant Dyeing, stannous chloride, used as a mordant in dyeing and calico printing.
 Tin penny, a customary duty in England, formerly paid to tithingmen for liberty to dig in tin mines. [Obs.] --Bailey.
 Tin plate, thin sheet iron coated with tin.
 Tin pyrites. See Stannite.
 tin pyrites
      n : a dark gray mineral with a metallic luster that is a source
          of tin [syn: stannite]