South Africans are demanding King Charles give them back the world's largest clear-cut diamond

South Africans are calling for King Charles III to return the world's largest clear-cut diamond to them.

The Star of Africa is set in the British royal sceptre and will be clutched by the new monarch at his coronation this weekend.

The diamond is officially called the Cullinan I, cut from the Cullinan diamond, which was a 3,100 carat stone mined near Pretoria.

The Cullinan I is a whopping 530 carats and is the crowning jewel of the royal sceptre.

Two years after it was discovered in the early 1900s, it was presented to the British monarchy by the South African government of the time, which was then under British rule.

As pressure mounts on the British to return artworks stolen during their rampant colonisation of the world in times now past, some South Africans believe the gift to their former monarchy should be returned to them.

The Print Collector / Alamy. GRANGER - Historical Picture Archive / Alamy.

Lawyer and activist Mothusi Kamanga started an online petition calling for the Star of Africa to be restored to its homeland.

The Johannesburg attorney has wrangled 8,000 signatures so far.

"The diamond needs to come to South Africa. It needs to be a sign of our pride, our heritage and our culture," Kamanga said as per Retuers.

"I think generally the African people are starting to realise that to decolonise is not just to let people have certain freedoms, but it’s also to take back what has been expropriated from us."

A smaller diamond cut from the Cullinan diamond, which is known as the Cullinan II.

That one is set in the Imperial State Crown, worn by British rulers on ceremonial occasions.

Both diamonds, set in their respective crown and sceptre, are usually kept with the crown jewels in the Tower of London.

However, King Charles III's coronation this weekend will be one of those rare occasions where they will be in public view.

In South Africa lies a replica of the whole Cullinan diamond, which is about the size of a massive fist.

It is displayed at the Cape Town Diamond Museum.

frans lemmens / Alamy

University of South Africa associate professor of African Politics Everisto Benyera told Al Jazeera that all proceeds of colonialism, the slave trade, and imperialism, are illegitimate transactions and the diamond should therefore be returned to its home state,

"As such, whether the British monarch purchased the Cullinan diamond at a nominal fee, or whether it was gifted to them by the Transvaal government, does not negate the fact that this transaction occurred within the broader occurrence of colonial relations," he said.

"The British monarchy must play its part in breaking this colonial relationship by acknowledging the role that it played."

Benyera added: "And one of the biggest ways that it can be acknowledged is to stop using our diamonds on their regalia, is to stop using our resources during their ceremonies, because …we are no longer part of the British Empire."