The name titanaugite refers to moderately to strongly coloured (brown to purple in plane light) Ti-rich clinopyroxene that commonly occurs in alkaline rocks.  The euhedral grain shown here has colourless zones near the core, mantled by a pale brown overgrowth in plane polarized light (A).  Viewed under crossed-nicols (B), the hourglass-shaped sector zoning that is characteristic of titanaugite is apparent.  Maximum interference colours of titanaugite range to mid-second order, although this grain is only first order grey.  Sample is from a basalt from Falkenstein, Norway. Both views are 5.5 mm across.  A ppl, B x-nicols.