A debate rages within the jewelry community, especially among those dealing with precious stones. Many precious stones are enhanced or altered.
Green oil is forced into the cracks of emeralds .
Nearly all blue topaz on the market began as a different shade. The premiere bead mineral, quartz, has been altered for millennia. So common are these alterations and so impossible is it to get the desired effect without altering, that it is widely agreed that a dealer need not disclose that these stones were altered. One of the most common, and to most people surprising, alterations is done to make carnelian . Look at the three stones above.