A billion-year-old black diamond, believed to be the largest cut diamond on Earth, is going up for auction. There are competing theories about the origins of the gem, named The Enigma, including ...

There was a time when a moral ... but we could not do without our coals. The Koh-i-Noor diamond is valued at $2,500,000—a sum which could purchase 590,000 tons of coal. If this diamond was ...

Glittering stars in the night sky aside, scientists have long known that there ... of meteoritic black graphite) within the hurtling meteorite itself transformed instantly into diamond during ...

and "What are those black diamonds for?" The answer to the first ... help you find multiple studs in a wall without making ...

qualify as triple black diamonds because of the consequences—if you fall here, you might not stop for a long time. Or slide over a cliff. Yet, just because a resort doesn’t have triple blacks on its ...

But which precious stones are rarer: diamonds or emeralds? In terms of total known deposits, emeralds are rarer. There are 49 emerald deposits, according to a 2019 review in the journal Minerals.

There's a huge demand for black opal, with lack of supply driving ... In the '80s and '90s, gem-quality brown diamonds were worth about $1,500 per carat, but now many sell for up to $10,000 ...