The Collaborative International Dictionary of English v.0.48:

Naphthazarin \Naph*thaz"a*rin\, n. [Naphthalene + alizarin.]
   (Chem.)
   A dyestuff, resembling alizarin, obtained from naphthoquinone
   as a red crystalline substance with a bright green, metallic
   luster; -- called also naphthalizarin.
   [1913 Webster]