Source : Webster's Revised Unabridged Dictionary (1913)

Tin \Tin\, n. [As. tin; akin to D. tin, G. zinn, OHG. zin, Icel.
   & Dan. tin, Sw. tenn; of unknown origin.]
   1. (Chem.) An elementary substance found as an oxide in the
      mineral cassiterite, and reduced as a soft white
      crystalline metal, malleable at ordinary temperatures, but
      brittle when heated. 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] --Beaconsfield.

   {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}.

Pyrites \Py*ri"tes\, n. [L., fr. Gr. ?, fr. ? fire. See {Pyre}.]
   (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}, or {Copper}, {pyrites}, the sulphide of copper and
      iron; chalcopyrite.

Source : WordNet®

tin pyrites
     n : a dark gray mineral with a metallic luster that is a source
         of tin [syn: {stannite}]