Where are crystal rocks usually found?
There seems to be some misconceptions running around this question. In geology, the term “crystalline rock” is usually used to designate those rocks that form under high temperature conditions. The noncrystalline rocks are those that form under low temperatures. So, for the most part, the crystalline rocks are metamorphic and igneous rocks and the noncrystalline rocks are the sedimentary rocks. There are some exceptions to these generalizations, but they hold true for the most part. So, crystalline rocks are found anywhere where you would have igneous or metamorphic rocks. BTW, just as a side note there is a fairly easy way to tell the difference between a crystalline rock and a noncrystalline rock. In small pieces (such as those one might use for a wind chime), crystalline rocks will tend to ring when struck. On the other hand, noncrystalline rocks will tend to have a much duller sound. This is because the void spaces in the sedimentary rocks tend to inhibit resonance.
