Many, many, many of the so-called gemstone beads on the market today are actually made in glass, typically by manufacturers located in China, India or Indonesia.  One way to determine whether the beads you have bought are genuine gemstone is destructive testing.  Take a hammer, wrap a cloth around the bead, and break it with the hammer.  Then, examine the sherds with a jeweler's loupe of at least 10X.  Perfect symmetry under the loupe usually means a 'fake.'  Another 'tell' is if any of the 'gemstone' beads have bubbles....while these manufacturing processes are very convincing, they're not perfect.  Ask your dealer what the beads are made of.  While many of them don't know, some are honest enough to tell you, 'glass.'