This is an example of a raw, natural amblygonite stone found in ... in the world is tougher than with more well-known gemstones, this purple axinite gem from Tanzania is remarkably clear with ...

At the far end of the color spectrum, we find purple gemstones ... of the sea besides coral, the natural pearl is one of the most sought-after and popular gemstones in the world,” Salzer says.

and show which gems are natural versus synthetic. “We showed the main spectroscopic characteristics of gemstones from these Middle East localities to distinguish them from their counterparts ...

They have identified elements that influence gems' color, differentiated stones found within and outside the region, and distinguished natural from synthetic. Since ancient times, gemstones have ...

With about 100 gemstones ... at pearl farms. Natural pearls are usually white or cream in color, while cultured pearls come in a range of hues, including pink, blue, purple, brown and black.

The Earth’s surface is also three-quarters water, and valuable gemstones like corals and pearls ... marine oysters and freshwater mussels as a natural defense against irritants such as a ...

The Smithsonian’s National Museum of Natural History will put the “Lion of Merelani,” which is one of the most finely detailed colored gemstones in the world, on public view starting Thursday.