The Colenso Diamond is an uncut octahedral 133 carat diamond, found in South Africa in 1883, (most likely in the De Beers mine). It was one of the earliest notable large diamonds found there. The story of how it was found is most tragic; a storekeeper South Africa left his shop and went into the country to go diamond prospecting. He invested (along with two partners) two thousand pounds in a claim and began digging. After a while, the claim appeared to be valueless, so the storekeeper and one of the two partners left, leaving the third man to mine on his own.

Sadly, the workings fell in on the man, killing him. This type of accident was not uncommon, due to the chaotic conditions of early mining in South Africa.

After a few months, the storekeeper returned, to recover the body for burial. When he dug up the remains, he also found a large rough diamond. He brought the diamond to England, and sold it to RC Nockold, a diamond merchant.

The diamond was shown to John Ruskin, an author, art critic, social reformer and voice of good taste in Victorian Britain. (Ruskin was a frequent visitor to Nockold’s shop, and was quickly sent a note to inform him of the arrival of an important piece of stock). Amusingly, Ruskin had mis-read the note, and was expecting a 13 carat diamond, not a 130 carat one! Ruskin had always advised people to wear their diamonds uncut, so was no doubt captivated by the diamond. In his book Deucalion and other studies in Rocks and Stones¬†he wrote, “For literal truth of your jewels themselves absolutely search out and cast away all manner of false, or dyed, or altered stones. And at present to make quite sure, wear your jewels uncut; they will be twenty times more interesting to you so.”

Ruskin bought the diamond for a thousand pounds, and he and his secretary spent a long time studying the diamond and making sketches of it. Ruskin was friends with the Keeper of Minerals in the British Museum, and, in 1887, presented the diamond to the museum, on condition that it be displayed with the following description:

The Colenso Diamond, presented in 1887 by John Ruskin, in honour of his friend the loyal and patiently adamantine First Bishop of Natal.

The Bishop of Natal was John William Colenso, a close friend of Ruskin. He was a notable mathematician and scholar of the Zulu language, who wrote a Zulu-English dictionary with over 10,000 entries! A champion of Zulu interests, he became known as “Sobantu”, meaning “the father of his people”.

The diamond was on display for over 70 years, when, unfortunately it was stolen in a robbery in 1965.

David John Knight was arrested about six months later, and was found guilty of the theft. The stepson of the Head Warder, he lived in the residence of the museum. He was sentenced to three years. It was later claimed that he had been framed for the theft by two officers who were later found guilty of corruption. The investigating officer gave evidence that Knight confessed, and had stated that the diamond had been shipped to Denmark.

The diamond was never recovered.