Diamond discovered by Canadian company among the world’s biggest rocks

A diamond believed to be one of the largest in the world has been discovered in a mine in Botswana by Vancouver-based Lucara Diamond Corp. The 1,111-carat gem measures 65 millimetres by 56 mm by 40 mm — a rock weighing half a pound that’s nearly the size of a tennis ball.

It joins some fairly weighty company in the record books. Here were the Top Five largest rough diamonds to date prior to its discovery:

1. Sergio: This black diamond, discovered in a Brazilian mine in 1895, weighs in at a whopping 3,167 carats, or 633 grams — bigger than a pound of butter, which is 453 grams.

2. Cullinan Diamond: The rough diamond discovered in 1905 clocked in at 3,107 carats or 621 grams, but the gem earned more notoriety once it had been cut. Some of the pieces from the original have now found their way into the crown jewels of the United Kingdom.

3. Excelsior Diamond: This 971-carat diamond — or 192 grams, about the size of a small orange — was discovered by accident in 1893 by a South African mine worker and later cut into 10 much smaller stones. One former manager of famed jeweller De Beers described the decision to cut the stone into “the greatest tragedy of modern times in the history of famous diamonds.”

4. Star of Sierra Leone: Iconic jeweler Harry Winston paid hansomely for this diamond, which was discovered in 1972. The stone, weighing 969 carats or 194 grams, fetched just under US$2.5 million in the currency of the day. Six of the 17 smaller gems cut from the diamond were later arranged into the famous Star of Sierra Leone Brooch.

5. Incomparable Diamond: This stone, measuring 890 carats or 178 grams, was reportedly discovered in 1984 by a young girl playing near a mine in the Democratic Republic of the Congo. She discovered the massive brown diamond among a pile of rubble that had been discarded from the mine. It was ultimately cut into 15 smaller gems.