еще один архив: popgun.ru/viewtopic.php?f=49&t=544667
из блога: http://www.liveinternet.ru/users/oldtor/post259689743/
чередование слоев у этих камней связано с приливами и отливами
темы об этих камнях на форуме SRP ( с качественными фото ):
Vintage Hindostan Whetstone Hone in Original Half Box
This is an interesting vintage Hindostan polishing stone that comes From French Lick in Orange County, Indiana, USA. The slabs were used as tombstones at one time! A colloquial name for them is 'orange stone' - not because of the colour, but because they come from Orange County. I haven't really experimented with it much, but I have found that it is exceptionally hard, it has a glass-like surface sheen and it leaves a very finely polished bevel - it is a very fair, slow acting finishing or polishing stone. It is very like a translucent hard white arkansas stone I once had - certainly it seems to be composed of the same, hard, glassy material (novaculite) but it is not really translucent. It has a curious coffee and cream colouration with yellow and orange banding and if you look at the edges you can see lots of small banding/lines which look like sedimentary layers, but the stone will definitely not cleave along these lines - clearly it has undergone some sort of metamorphosis during its creation that has left it exceptionally strong and hard stone.
It has a small fracture line visible - the fracture is on one side and extends approx half an inch on one of the largest surfaces and approx. three quarters of an inch on the other. It is more of a hairline mark, and the stone itself is sound - I have honed several razors on it and the mark does not affect honing in the slightest. It has two clipped corners as can be seen in the photos. The stone measures 8 and 3/8th inches long by 2 and 3/16th inches wide by 1 and 1/16th of an inch thick (2124mm x 57mm x 29mm). It was once used with oil but has cleaned up well, although there is still a faint oily smell. Any tendency for water to bead on the surface is easily overcome by adding a little dish-washing soap to the water. The stone has now been wrapped in clingfilm and put back in its half-box (it comes with a fitted wooden half-box, made from varnished timeber - not in great condition and not pictured, but an admirable packing in which to post the stone.
Although they were once used to make to make headstones for tombs the original use was as a whetstone. The quarries were first worked around 1825 by the Prentiss family who had settled in a town in Martin County called Hindostan. The worked stones were transported by boat to New Orleans and from there it was shipped to New York and England. In England it caused a lot of controversy because of the name - it was believed the item was a fraud because Hindostan was not believed to be in America, and this nearly stopped the mining operations. However, work continued and after a change of ownership the mines were producing 4,000 cases of product each year, about half of which found its way to England and some to South America. The last remaining quarry closed in the 1980s.
The pictures with a red backdrop show the stone dry - it has been covered in water for the remaining photos. Each time I have used it the surface has got even more glass-like and it can mirror objects like the light bulb over my honing station. It is very slow in use - about 50 laps produce a noticable polishing and a hundred or more laps take nearly every little scratch out of the bevel of a blade. I would say its speed is roughly on a par with a translucent arkansas or a chinese 12k guanxi stone. I'm not sure about a grit rating on this one - it leaves a very fine scratch pattern on the bevel and if I had to compare it to a grit rating, I suppose that I would be a bit conservative and say somewhere between 10k and 12k, but your experience may be different to mine - as far as I am concerned it has an unknown grit equivalence! It is lapped on both sides and is acceptably level to hone on in my opinion, but you may wish to lap it some more to suit your own preferences. With more laps than I have done the bevel would undoudtably get more polished, and with a fine honing oil it could exceed my estimate.