After looking at a variety of mineral samples, physical science students examined unknown minerals and used their knowledge of mineral properties to determine the identity of the samples. A mineral’s streak, luster, tendency to react with hydrochloric acid or not, cleavage, crystal form and color provide clues. Because mineral samples can contain impurities this is not as easy as it might seem to be.
Samples of minerals included halite (salt), pyrite (fool’s gold), fluorite (our state mineral), feldspar (becomes clay), quartz (becomes sand), gypsum (wallboard and chalk).