Now made public.
I found this lump of jet last week, and the seller thought it was obsidian, or volcanic glass.
I picked it up and realised it was too soft and light for glass, then I realised what it was. I don't understand why they call jet 'fossilised coal', because I thought coal was in itself a fossil. Maybe 'metamorphosed coal' would be a better description? This is quite a big lump at one pound three ounces.
I don't know much about it, but I do know that there was a large, Victorian industry in mourning jewellery - probably started by Queen Vic herself - and it centred on the fishing town of Whitby, where it could be found on the shoreline, in amongst the stones and pebbles.
I suppose it is possible that Bram Stoker had Dracula land at Whitby because of this association with death as well. We associate the colour black with death and darkness, and you cannot get much blacker than jet.
There was such a market for jewellery made from Whitby jet, that substitutes were made in black glass which - ironically - is much harder to work than real jet. Maybe they started running out, or cornering the market?
I think this lump is the remains of the Victorian jewellery business, because it has been split up, and there is a flat section where a piece has been cut off. It also shows signs of having been sat on a shelf for many years too.
I don't know what it is actually worth, but I am about to find out, as I put it on eBay for sale recently. At the moment, it has reached 99p...
I suppose that - like diamonds - it burns quite nicely. I begin to imagine an inhabited planet with a similar climate to Britain, which has diamonds in such abundance that they are shovelled up and used for fuel in homestead fire-places.
I wonder if this planet has eBay as well?