Discussions

💬 Home 🔎 Search 📅 Latest

╳Discussions

💬 Home 🔎 Search 📅 Latest

Groups

Recent Images in Discussions

Identity HelpBeamsville Quarry specimen?

28th Sep 2009 19:10 UTCAndrew Johns

Hi all, I was lucky enough to attend the trip to Beamsville this past Saturday. I found this piece of Limestone with white Dolomite xls which has been covered with a yellow substance. I was told it was Barite? Also there are some yellow micro rosettes which I think are Sphalerite. The yellow coating I think may be Sulphur? There is also nice Pyrite needles and possibly some Marcasite on the piece as well. It's a really nice piece. I'm sure someone has found something similar.

Can anyone help?

Thanks Andrew.

28th Sep 2009 19:37 UTCsteven garza

Dear John;

I doubt those sprays are barite, but, sacrificing a small one & dropping it into a drip of HCl, should clarify if it's barite. I'm thinking, with the bent "staghorn" needle aggregates, that it might be strontianite. Most collectors don't know that much of the barite from Illinois to Ohio to Ontario has quite a bit of Sr substitution in the barite & when the barites break down, the strontianite is more likely to xlize out. If it fizzes, it's a carbonate (knocking out barite). Take the resultant solution (let it continue to work on the spray until the fizzing stops) & soak a wooden match stem in it 7 let dry; then, ignite it in a candle flame & check to see if the starting flame flashes red, before the wood really gets going. if it does, that confirms the presence of Sr. From that point, it's either strontianite or strontian aragonite; seeing that celestine is listed as found there, strontianite is MUCH more likely to be the answer.

The yellow rosettes are, indeed, sphalerite.

It looks like most of the metallics are marcasite (they look like the flat "Roman broadswords") & the few rectangular rods are the pyrite.

Altogether, some nice specimens & you MAY have a new locality mineral list entry, to boot!

Your friend, Steve

28th Sep 2009 21:05 UTCMaggie Wilson Expert

Hi Andrew - I'm the "spokesperson" only here: Reiner says, "barite."

28th Sep 2009 21:29 UTCAndrew Johns

Hey Steve, it's Andrew not John. Lay off the :)o I will try that test if I can manage to sacrafice a piece but I don't really want to damage it. It is a micro after all.

your friend Andrew..

28th Sep 2009 22:07 UTCAndrew Johns

Thanks for the input Maggie, It looks like Barite I just wanted some more opinions. I'm sure Reiner knows the minerals well from Beamsville.

Thankyou, Andrew.

1st Oct 2009 18:27 UTCTim Jokela Jr

The mineralogy of Beamsville is dead simple. I'd call that barite, but would suggest you do that very interesting test. I'm not sure if that stuff has been analyzed. The brassy needles you'll probably find are all marcasite. Magnification tells all. Reminds me that I should write up that locality to clear things up.

T

1st Oct 2009 20:06 UTCReiner Mielke Expert

The match thing sounds like a neat idea. I usually use a nichrome or platinum wire with a tiny loop in the end. You powder a sample, dip the loop in HCL ( after you clean the wire ) and then touch the powder. Then you place the loop in edge of the flame of an acohol lamp or propane torch. You will get a red flame near the wire for strontium, or green if barium. The match thing sounds much easier, I'll have to try it. Not sure if Barium would show with the match though, probably too much sodium that would mask the colour, we'll see.

2nd Oct 2009 16:54 UTCsteven garza

Dear Andy (I got it right, THAT time; I swapped your last name for your 1st, last time. LOL);

using a sewing needle as a pry, you should be able to remove the smallest "x" spray, that's on the lower left part of your 1st pictured specimen (I'll tell you how to make your own set of micro-tools, from ordinary steel nails & a blowtorch, later; may even SEND you a set, in next trade); believe it or not, that's all that would be necessary. Observe any acid action, on a drip of acid on a piece of clear colorless plastic/glass/microscope slide & put the sample on the slide & push into the drip (all while under the microscope). if it "flash fizzes", disregard that & consider it barite; if it continues to fizz, that means it's a carbonate. It's the "curved fishhook" features that you also see on PA, OH, & KY strontianites that is making me think that's a possibility. I've also collected barites, with similar structure, but, not as curved xls. Not saying it isn't so, but, there IS the possibility & the damage to the specimen would be near non-existant (you DID say it's a micro, so, the damage would be micro!).

To the others;

be sure to use a WOODEN matchstick; preferrably one you haven't handled at the end (use steel tools, to insure this). The reason I don't use paper is it WILL have added NA, as well as Ca (from binding clay) & S (from pulp treatment), which WILL mask Sr & Ba response. Putting the crushed sulfate & HCl on the matchstick gives near same response as on wires. If Andy's X IS a carbonate, the red flash will be VERY pronounced. WARNING ANDY! the response will ONLY be a flash! very 1st thing, as the match starts to burn & will be in the flame zone closest to the flame cone.

Your friend, Steve

4th Oct 2009 18:48 UTCAndrew Johns

Ok, I managed to find some similar sprays on another piece I collected there. I'm hoping to try the test this week sometime. Even if it is Barite it's a great test for me and a good learning experience. I'll let everyone know the results.

Andrew..

10th Oct 2009 06:46 UTCAndrew Johns

Ok all, I tried the test tonight, now I used a wooden toothpick instead of a wooden match. I did not get even a small flash of red but I did get a very, and I mean very weak color af green. I'll consider it Barite. Thanks Steve and Reiner. A very useful and easy test.

Andrew..

14th Oct 2009 18:30 UTCPeter Haas

"You powder a sample, dip the loop in HCL ( after you clean the wire ) and then touch the powder. Then you place the loop in edge of the flame of an acohol lamp or propane torch. You will get a red flame near the wire for strontium, or green if barium."

One general note (likely doesn't apply to this specific locality, but important to know):

If your sample contains copper compounds, the test, when carried out as described, will give a bright green flame, no matter whether barium is present or not. This flame reaction is a general property of copper halides and is known as Lassaigne's test (NOT: Lasagne). It is due to contamination of your sample with chloride (from HCl). Better use HNO3 to digest the sample in such cases.

Go to top of page