If you want to know whether a diamond is real, breathe on it. Diamonds are very efficient heat conductors, so the fog from your breath will disappear almost immediately if it is real. If the fog sticks around a few seconds before clearing up, the rock is probably a fake.
The “Star of the South”, one of the largest diamonds in the world. Discovered near a river in Brazil in July 1853, it was found by a slave girl named Rosa, who turned the diamond over to her master. He rewarded her by granting her freedom and giving her a pension for life.
Photo : Chris 73 / Wikimedia Commons
There are enough diamonds in existence to give everyone on this planet a cupful.