Chinese Snuff Bottle Discussion Forum 中國鼻煙壺討論論壇

Public Forum Categories and Boards => Gem, Stone, Rock and Fossil => Topic started by: cshapiro on May 30, 2017, 01:19:13 am



Title: Mystery Hardstone
Post by: cshapiro on May 30, 2017, 01:19:13 am
I recently got a bottle that I could have sworn was jade from the pictures, when it came I was sure it was agate, but it's specific gravity is 2.51 so now I don't know what it is.

It's definitely a stone of some type.

So my question is, could the specific gravity be off .14 points? Maybe my scale is off! Or is there something else this could be made of?

thanks in advance!

(https://snuffbottle.smfforfree.com/proxy.php?request=http%3A%2F%2Fwww.flashprodesign.com%2Fchinese%2Fagateorjade.jpg&hash=49340a7c96e377853bbe15f8ddde9735)


Title: Re: Mystery Hardstone
Post by: Wattana on May 30, 2017, 01:31:31 am
Cathy,

This definitely look like jade to me, not agate. Could your test have been slightly off?
Have you tried a scratch test?

Tom


Title: Re: Mystery Hardstone
Post by: cshapiro on May 30, 2017, 02:12:05 am
Yes Tom, I agree! The markings really looked like jade. I hate to admit but I have been doing all my specific gravity tests on my kitchen scale so I really need to invest in a better scale.

On hardness, I see jade is 6-7 and agate is 7 - I just tried glass, and when that didn't scratch, I tried a steel knife from my kitchen and thankfully - no scratch! Not sure what I have on hand to try to go higher - any suggestions?

I have read that there is a margin of error on specific gravity - depending on the makeup of the stone itself - so my best guess it that it's chalcedony that is just a little heavier in water - hence the lower specific gravity. With the SG that low it couldn't possibly be jade I'm thinking.


Title: Re: Mystery Hardstone
Post by: Wattana on May 30, 2017, 03:14:30 am
Cathy,

There are many grades of steel, all with different degrees of hardness depending on the amount of carbon, manganese, vanadium and other additives, so knive blades are not the most reliable tools for a scratch test. I use Mohs' standard kit of minerals, which you can buy from a gemology supplier. In that kit orthoclase feldspar is the "next one down" on the scale from quartz.

But from the specific gravity test it looks like you have to rule out jade. Another test is a visual one. If you have a x10 magnifying loupe both nephrite and jadeite will show a structure of overlapped asbestos-like fibers, while quartz, being a crystalline stone, will not show such a characteristic.

Tom

PS: Now that I look at your bottle again the reddish markings in the first, fourth and fifth pictures show a net-like pattern, which is similar to one I have seen on chalcedony bottles, like the one posted below.


Title: Re: Mystery Hardstone
Post by: cshapiro on May 30, 2017, 11:02:49 am
Yes, I think the mystery is solved!

Thanks Tom!

By the way, I just purchased a Mohs hardness kit for $20 - no excuse not to have one!


Title: Re: Mystery Hardstone
Post by: George on May 30, 2017, 11:54:51 am
Beautiful bottle Cathy... Looks like chalcedony to me too..

Congrats !


Title: Re: Mystery Hardstone
Post by: cshapiro on May 30, 2017, 02:31:13 pm
Thanks George! It is a pretty bottle! I imagine you can tell from the pictures that it's shaped like a peach, and has the monkey and peach rebus which is one of my favorites. I think it would be even more beautiful if I could remove the old snuff stains inside - I might try soaking it in some water and dishwashing liquid to see if it comes out.


Title: Re: Mystery Hardstone
Post by: rpfstoneman on May 30, 2017, 08:33:40 pm

Cathy,

I use cotton swabs dipped in alcohol on occasions, and that seems to work.

Charll


Title: Re: Mystery Hardstone
Post by: cshapiro on May 30, 2017, 08:41:32 pm
Ah! Great idea Charll - I will try it!


Title: Re: Mystery Hardstone
Post by: AntPeople on May 30, 2017, 09:46:56 pm
Hi Cathy :

Interesting bottle... like the way the they use the natural pattern of the stone to carve up the fruits and also the monkey head

Congratulations

Pin


Title: Re: Mystery Hardstone
Post by: cshapiro on May 31, 2017, 10:21:55 am
Thanks Pin!

On removing the old snuff, the q-tip and alcohol work to a point, but I will need patience because most of the tobacco seems to have stuck into the rough crystals in the interior walls, so they are pretty well established I'm afraid.

I have been re-reading "Chinese Snuff Bottles of the Silica or Quartz group" and this bottle doesn't seem to fit into any of the categories.

The bottle appears to be carved similar to some jade bottles I've seen. Could anyone suggest a book that has more about jade carvings?