Category Archives: Books

The biggest diamond in the world? Ever?

Yellow Topaz with smoky quartz from China. PHOTO: Rob Lavinsky http://www.irocks.com

(more notes from the notebooks in the attic)

There are no pictures of the great Braganza diamond, and nobody knows quite where it might be. But here’s the story, and the mystery.

In around 1790, three criminals were banished “into perpetual exile” in the interior of Brazil. The rule was that they could not go into any big towns – and if they did so, they would be imprisoned for life.

The three men decided to try their luck mining in the Rio Plata area, hoping that a big find of gold might reverse their fortunes and maybe even, with some bribery funds, their sentences. In 1797, after six years of searching (and avoiding cannibals and government soldiers on the way) they came to the river Abaite. It was a drought and the waters were at their lowest levels known in living history.

While panning for gold they were surprised to find, in one of the pans, a stone of excellent heft that weighed nearly an ounce. A clergyman helped get them access to the governor at Villa Rica who consulted a jeweller to decide whether the stone was or was not a diamond. It was decided that it was, and the men were pardoned. It does not appear that they were allowed to keep the jewel.

It was called the “Braganza”, after the Portuguese Royal House of Braganza. However now the stone has disappeared from sight, and it is believed by many experts not to have been diamond but topaz.

Edwin Streeter notes there are other accounts and many possible weights attributed to the Braganza. He tells a story of the German Aulic-councillor Beireis of Helmstadt, who possessed a stone he believed to be a diamond – weighing 6,400 carats. He kept it locked up in a cabinet and spread the story round that he had received it from the Emperor of China. “Nobody of course believed this story, but the strangest part of it was that at his death [in 1809] the stone had disappeared” – even though Goethe himself testified to its existence. It could be that he loved mystery, or it could be that he wanted to save his reputation by preventing the true character of the gem from being known. “It is well to remember that the topaz, which consists of a fluorosilicate mixed with silicate of aluminium is apt to be mistaken for the diamond by unpractised eyes.” (p.45)

A final note on the Braganza, Portugal has not has a King since 1932, when its last monarch, the exiled Manoel II, died at Twickenham, after a day of watching tennis at Wimbledon.

More on topaz on the latest “The Ones that Got Away” page.

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An enormous garnet, discovered in a sewer

The finest large garnet crystal

The sewer garnet is part of the seal of the NY Mineralogical Club

I’ve just looked back at my old notes on garnets – thank goodness they didn’t all disappear, quite, with my ancient hard drive – and have been reminded of the jeweller George Frederick Kunz’s excitement in 1885 when what he estimated to be the finest large garnet crystal found to date in the United States, was found in a sewer.

“It was discovered, strange though it may seem, in the midst of the solidly-built portion of New York City” below W35th Street (between Broadway and Seventh) by a labourer who was digging for a sewer. It had not, incidentally, been lost in the sewer – garnets were evidently simply part of the bedrock of Manhattan. It was almandine, which is a nice way of saying purply-brownish, “weighed 4.4 kg, and was partly a trapezohedral shape”. Trapezohedral is the kind of description you skip over with ease, initially, thinking you know what it refers to, then in my case at least you realise you don’t have the first idea. Wikipedia describes it as ‘the dual polyhedron of an n-gonal antiprism” which didn’t help, but the illustration below is a good way to picture it. Since dubbed the “sewer garnet” it is now, apparently, part of the seal of the New York Mineralogical Society and I’m told by one of my very first blog readers (thanks!) that it can be seen at the American Museum of Natural History in New York in a place in the gallery that isn’t that obvious… so please get hunting, and let me know if you find it.

The Kunz garnet - New York Academy of Sciences Transactions 5. (1886)

You can find a few more of my random and unused notes on garnets on my new, to-be-expanded, “garnets” page here. Also, if you’re interested in the sewer garnet, the John Betts website has a good account of some of the happy and unhappy controversies and correspondences its discovery inspired.

Pepys struggled with reading a book on Colours

I have just received a lovely letter from Mr Kenneth Bone in Stirlingshire, telling me about one of his favourite quotations from Samuel Pepys’ Diary (Vol 2).

2nd June 1667 (Lords Day)

Being weary and almost blind with writing and reading so much today, I took boat and up the river all alone as high as Putney almost, and then back again, all the way reading and finishing Mr. Boyle’s book of Colours, which is so chemical that I can understand but little of it, but enough to see that he is a most excellent man.”

Pepys was talking about Robert Boyle’s Experiments on Colours, published in 1663, and Mr Bone wondered why I hadn’t mentioned it in my bibliography of Colour: Travels through the Paintbox. I’m ashamed to say that I hadn’t even found it, let alone struggled through the chemistry of it.

However since then, Gutenberg, that wonderful free library institution (for which I helped on the inputting of a couple of fantastic obscure books a few years ago, which I’d recommend to anyone who likes that kind of thing) has now put it online.

It starts with a short Preface, expressing a concern that I have some sympathy with:

Having in convenient places of the following Treatise, mention'd the
Motives, that induc'd me to write it, and the Scope I propos'd to my self
in it; I think it superfluous to entertain the Reader now, with what he
will meet with hereafter. And I should judge it needless, to trouble
others, or my self, with any thing of Preface: were it not that I can
scarce doubt, but this Book will fall into the hands of some Readers, who
being unacquainted with the difficulty of attempts of this nature, will
think itn strange that I should publish any thing about Colours, without a
particular Theory of them.

Read more of the 1664 book here, though apparently the best edition was published in 1852, with notes by John Holmes Esq, of the British Museum. Next time, some information from the Painter’s Companion, 1810, also sadly unquoted in my book, but deserving a mention.

Happy Thanksgiving to all those readers giving thanks.