stone is transparent while glasses of opaque
hiiii
1st of all your question is wrong.
the stonea are not transparent where as glass are transparent.
the transparency of a substance depends on the material of which the substance is made if beems of light reflected back after fall from the substance surface then the substance is called opaque or if the beem of light easily passes through the material then the substance is called transparent.
hope this will help you to understand
best of luck for your future