Field Trip Report - [NOT] Magnetite in Jade

Yep, I'm with you on the SG of your sample.3.4 is too high for nephrite. Nephrite is not supposed to be above 3.2 max and much is much lower still.

Serpentine marbles are very common and very popular in the building trade. Verde Antique is actually a trade name developed especially for serpentine bearing marble from many locations to indicate the green yellow tones of the marble due to the included serpentine, ie Verde=green. If you Google serpentized marble, you actually get verde Amtique. Sinkankas in his book, claims the magnetite bearing nephrite is actually sandwiched between two layers of the marble but as I've said, when I went to try to find it many years ago, my level of jade identifying skill was very low and I whacked a lot of rocks but found none I thought were jade.

The sample posted in the ID section definitely appears to have actinolite on the exterior that appears very much like the boulder you posted a p[ic of in your thread. If you go back up there, I'd pay special attention to any rocks that seem to have the actinolite very dense and compacted since nephrite is pretty much actinolite or tremolite in very compact form. Pretty much the same chemical makeup, just different structure...Mel

this is very interesting. I googled serpentine marble. We sell that stuff for flooring. I wonder why we put serpentine in peoples homes, but that is another bulletin board.

I need to read that book. When people speaking of verde antique being played out, that must mean all the serpentine marble is taken away. There are thousands of tons of marble left there. But it doesn't look like the serpentine marble google shows me.



Thanks again Mel. I am going to find that magnetite in jade if it still exists.

Scott. John Sinkankas wrote three volumes of Gemstones of North America but the last was published after he passed. I have all three with the first two being signed to me by John himself. That always tickles me pink as I love signed editions. For the type of use we put them to, the first two volumes are most useful. The third is just sort of an update to the other two. The first two are a wealth of information on lapidary materials with lots of state by state location information and history on a lot of the old finds. Probably one of my favorite sets of books to read.....Mel

Thanks Mel!!!

Mel et al; I am now all about Reibeckite. Sodium Iron Magnesium Iron Silicate!

This sample is not very different from my own.





Nate we welcome newbies here. I am a newbie! Only been playing with rocks for three years. There so much knowledge here. D not be shy. Some of these guys been cutting rocks longer than I been alive! Most enjoy sharing their knowledge. The friendliest group of folks on the entire internet.

aegirite/reibeckite same thing except reibeckite curiously adds a secon iron atom of a different valence. Reibeckite had bot Fe+2 & Fe+3!

Jadeite/aegirite same thing except jadeite has measurable aluminum.

I did do a test that should have been done a long time ago. I did a streak test.

Streak test = white

reibeckite has grey so not reibeckite.

jadeite & aegirite = white streak

I am going to have him run it again in the spectrophotometer to look specificallty for aluminum.

Try this

www.flickr.com/photos/100325085@N07/

Also, my avatar pic is a shot of the rock.

Yes, that mountain. I have some black jade, looks like your stuff until you cut into it, then jet black with some impurities. I also have a ton of stuff which I haven't identified yet, but could be serpentine or from that family. Might go up there Sunday.