Source : Webster's Revised Unabridged Dictionary (1913)

Sandarach \San"da*rach\, Sandarac \San"da*rac\,, n. [L.
   sandaraca, Gr. ?.]
   1. (Min.) Realgar; red sulphide of arsenic. [Archaic]

   2. (Bot. Chem.) A white or yellow resin obtained from a
      Barbary tree ({Callitris quadrivalvis} or {Thuya
      articulata}), and pulverized for pounce; -- probably so
      called from a resemblance to the mineral.