Possible Washington black jade??

[spokanetim]

I found this 9.5 lb rock a few months ago off the northwest part of the Columbia River and picked it up because it sort of had this funky green sheen about it. I took it home and hacked off a small piece of its side with the tile saw. The piece looked very dull and boring so I just tossed it aside wondering why I lugged it back.

Today I was surfing the web looking for places to go rock hounding and found some sites saying Washington has both green and black jade in the northern part of the state. The jade was most likely dropped here out of Canada in the last ice age. Looking at the black jade rough online I remembered that ugly rock and thought hmmmm, looks similar. I went out and found it under the snow, including part of the piece I sawed, still thinking it was probably nothing and started doing some of the tests for jade I read online.

It was cold, snow will do that, but it did hold the cold longer than I expected. I tried to scratch it with several knives and it wouldn't scratch no matter how hard I tried. Hitting the two pieces together it did make a nice "clinking" tone like beer bottles toasting. The rock is very dense and heaver than it looks. Then I took the little piece to my Genie and polished up the faces. The diamond grinding wheels put out a very dark green "mud" and then it easily polished to a glass finish on the 14,000 wheel. It doesn't really show in the pictures but there is a very slight green sheen in the polished piece. Finally there's no crystal structure to be seen, even with a 20x loop.

I've never seen jade rough and know nothing other than what I've read on the internet. So far it seems to be passing all the tests I read about. If it's black jade than from what little I could find online it could be very valuable rock and I'll kick myself for the cuts I've made in it's side.

If anyone has any opinions, one way or the other let me know! I know a guy here who could ID it but I don't want to make the 45 min. drive to his place until I'm a little more sure.

[deb193redux]

looks like some of the California jade. inside and out.

[MikeS]

hmmm...it could be jade, it does seem to have the felted layering typical of nephrite. It looks like it has a fair amount of inclusions, however. Have you tested the specific gravity? While it won't necessarily determine if it is nephrite jade, you can usually tell right away if it isn't. Nephrite should have an SG of 2.9-3.1. I'd try that next....

[Sabre52]

I used to buy quite a bit of jade from Washington state sources mostly from around Darrington. I've gotten blue. black, chatoyant, mossy, snowflake, chromoflec, zebra etc. I understand there are quite a few other areas in Washington yielding jade too....Mel

[spokanetim]

Had to look up how to do specific gravity! It's been way to many years since I've done that. So, the little cut piece had a wt. of 21 g and when suspended in a zeroed cup of water it added 7 g to the water. That would put it right at a specific gravity of 3! I also read that the black jade is magnetic due to the iron which makes it black and guess what, the rock will hold a magnet .

I literally did a 3 minute job polishing the little piece I put in the photo, no time with the kids running around. Now I've polished it better and it's so silky black. Makes you just want to rub it between your fingers. I don't know if the cracks are full inclusions or if just the outer layer is cracked from exposure. Looking into them they don't look like they run into the rock itself.

[spokanetim]

Thanks Mel, that's more good news. I'm starting to believe this is the real stuff. Blue Jade, that must have looked really nice.

[rockhard]

Aha, thanks for posting this. I find chunks of what might be the same stuff on the N Oregon coast. It cut like hard jade on the WF and I always wondered.