One of the largest gothic cathedral in Northern Europe hosted a fundraising dinneron June 8th to celebrate the Queen’s Diamond Jubilee.

Yet the 900 guests must have been surprised when they entered York Minster in northern England to find the floor of the Cathedral transformed into a lawn. While workers laid down 16,000 square feet of fresh grass that covered the stone floor of the 14th century church, it appears that the job of mowing fell to the priests. (Source)

The Argyle Pink Jubilee

The most consistent source of pink, purple and the very rare red diamonds is the Argyle mine in the remote desert wastes of Western Australia (see https://www.facebook.com/TheEarthStory/posts/516555285072187), and the annual tenders in Perth are one of the fixtures of the high end jewellery market since these special stones are usually cut in house so as to maximise the added value. There are only ever a few stones for sale over a carat, maybe half a dozen yearly. The largest rough pink ever found there (in 26 years ofoperation) is this slightly etched distorted octahedron, which weighed in at a puny 12.76 carats (2.552 grams). The colour is a pale but powerful rose, similar to the Williamson Pink, found in Tanzania and gifted to the Queen of England on theoccasion of her wedding by the mine owner.

Unlike most of the mine’s production, this stone ended up being donated to the Melbourne museum (where it on permanent display) after being the expected star of the show at an invitation only tender in 2012. Luckily for the world, when they started cutting it they found a knot, an internal line of stress and incipient cleavage reflecting the stone’s exciting geological history during the process of formation or eruption from the mantle in the lamproite pipe that brought it to the surface (these knots are known in the trade as a gletz). When the saw or scaithe (the round polishing disc) encounter these knots, the usual result is that the stone promptly explodes into shards as the internal strain is released.

The preshaping removed 4 carats (it is common to lose 40-80% of a rough diamond during cutting) before it was donated to the museum, but pieces like this almost never end up in such places in the rough. Rich patrons sometimes donate cut stones, such as the Hope at the Smithsonian, but commercial companies tend to sell all their rough. While they could have cut several smaller stones out of the rough, it was decided to donate it, since it had been the largest Argyle crystal ever found. Since the museum had a long standing relationship with Rio Tinto, they got the lucky prize. Next time I’m over that way I guess I’ll drop round and visit it. 


Image credit: BBC/Getty


one gifset per appearance → monarch’s lunch, windsor castle (18/05/2012)

Her Majesty Queen Elizabeth II and the rest of the British Royal Family received monarchs from around the world in celebration of the Queen’s upcoming Diamond Jubilee.