SSC MTS EXAM

Detailed explanation-1: -Luster describes the way a mineral reflects light. Measuring it is the first step in mineral identification. Always check for luster on a fresh surface; you may need to chip off a small portion to expose a clean sample. Luster ranges from metallic (highly reflective and opaque) to dull (nonreflective and opaque.)

Detailed explanation-2: -But mineralogists have special terms to describe luster. They first divide minerals into metallic and non-metallic luster. Minerals that are opaque and shiny, like pyrite, are said to have a “metallic” luster. Minerals with a “non-metallic” luster do not look like metals.