Jewelry designer Nina Runsdorf was at a trade show in the early 2000s when a “large brown rock” the size of a pebble caught her eye. The seller told her it was a rough brown diamond. Runsdorf, in ...

making them appear green. Whatever the reason, diamonds come in a rainbow of bright, beautiful colors, and then there are brown diamonds. For centuries, brown diamonds were cheap. They were ...

Brown diamonds are caused by the crystal becoming deformed ... Blue diamonds only need a tiny amount of boron to produce colour, but they are much rarer than yellow ones. A green diamond means it has ...