Opal is the traditional birthstone for October.It is believed the stone was discovered in India and given the name "upala," or "precious stone" in Sanskrit, the Geological Institute of America ...

Precious stones. Add Topic. ... This gemstone is well-known for its "play-of-color," or ability to shift color. Opals often have a kaleidoscope of colors on their surface.

Back in the day people were more relaxed about moving precious stones around the world. Consider, for example, the low-key arrangements for the famous Jonker diamond, which was shipped by ordinary ...

CAMBRIDGE, Mass. — The first blue pigment to hold its color was often prized over gold. The semi-precious stone lapis lazuli was ground into an iridescent pigment, sometimes called ultramarine ...