FMF - Friends of Minerals Forum, discussion and message board

[2 Bar A]

Sorry for such a long intermission...ok, here comes the next specimen...#85, 7cmX4.25cm black crystals on a white base. I have no idea what it is.

[2 Bar A]

And here's our next specimen it almost looks like a dessert! No number on this guy, measures 14.5cmx12cm...

[2 Bar A]

One more till tomorrow #10-32a 11.5cmX9cm

[Edelmin]

Hi Barbara,

Your first specimen today is a group of neptunite crystals (black mineral) on a matrix of natrolite (white). It comes from the Dallas Gem mine, San Benito Co., California.

The second is probably a tourmaline specimen (black long crystals) on albite (white). It may be from Minas Gerais, Brazil, it is very similar to specimens I have in my collection from there (but I have no more precise locality information).

The last one looks as hemimorphite on limonite but I am not sure from the pictures. May be anyone else can give any other choice.

Regards,

Felix Garcia

[Ed Huskinson]

Hey 2 Bars. #85 is neptunite from the Benitoite mine in San Diego County. The white stuff is natrolite, makes a nice contrast, eh?

Congratulations again on your windfall.

Ed

[Ed Huskinson]

Felix nailed it. The little black crystals are probably one of the tourmalines, schorl, dravite, one of those.

By the way, your neptunite comes from the same mine that produced California's state gem stone, the benitoite. I'm hoping that the collector has one in there for us to look at. It'll be bluish, and kind of triangular in aspect. We'll see.

But the last specimen is definitely hemimorphite, from the Ojuela Mine, Mapimi, Durango,Mexico. The orange matrix is earthy gossanous limonite, and the little black areas are probably murdochite. The real cognoscenti out there might even be able to determine some sort of vintage for the piece. I haven't seen one like this since about 1973 or so. But that doesn't necessarily mean anything. They're always rooting around in there, and batches of material from Mina Ojuela surface sporadically.

Keep it up!

Ed

[2 Bar A]

Thank you Ed and Felix for the ID's! You guys are great! I will now upload my next specimen....#20

[2 Bar A]

This one is amazing, it looks alien to me...#67 10cmX6cm

[Edelmin]

Hi again Barbara,

Specimen 20 is sphalerite (the black crystals and most of the matrix) with white calcite (may be some quartz as well but it is not sure) and probably small pyrite crystals (the golden cubes of the last photo).

Specimen 67 is carborundum, a synthetic compound very often mistaken as a mineral species (it is usually sold at rock shops, flea markets, souvenir shops) but it is not natural.

Regards,

Felix Garcia

[Ed Huskinson]

Yes 2 Bars, Edelmin is doing all the heavy lifting here. It is possible that the black sphalerite (marmatite) is from Santa Eulalia. Possibly Naica. Both mines are in the state of Chihuahua, in Mexico. Pete will straighten this out for us when he returns from wherever he's roaming.

The carborundum is artificial. They grind it up and use it to make sandpaper, and other abrasives. It's pretty though, I'll grant you that. Wait till you learn about bismuth....

More! We want more.

Thanks,

Ed

[Singingstone48]

Barbara,
We are happy you are finally putting this collection back in the light of day! Many of these were probably obtained in the 1970s to 1980's. The general size of the specimens is very nice to see. I agree with all the identifications done so far. I will bet the sphalerite with calcite and pyrite is from Naica, in Chihuahua, Mexico, but I'll defer to Peter's greater knowledge when he gets back online. I like the way you are imaging the specimens, with a closeup and a whole view. Are you able to use a small tripod to steady your camera? If not, an expenditure of less than $20 will get you a table top tripod that will handle a compact camera nicely. That and learning how to use the self-timer on the camera will improve your shots immensely. I second the other posters. Keep the specimens coming. It's like looking at a time capsule being opened.
Steve

[2 Bar A]

Hello everyone,

Im back! I’ll bet you thought I got stuck in a mine shaft somewhere in Namibia…but nothing that exciting! I’ve actually been busy photographing my collection. I took Steve’s advice and used a “tripod” that I made myself and hooked my camera up to my computer so I could make adjustments and take pictures from there. I also took some pictures in the good old sunshine using home made light diffusers. Let me know what you think. Oh and BTW: The halo that you see around the super close-up shots is from an 8X magnifying glass, the kind jewelers use. I’m kind of a “Macgyver” when it comes to this stuff. Plus I’m broke so I can’t go out and buy tripods, light boxes or macro lenses…

Okay here is the next specimen, #5 measures 6.5cmX6cmX3cm

[2 Bar A]

Here is specimen #72 measuring 7cmX5cmX3cm...

[2 Bar A]

And here is #105 measuring 11cmX8.5cmX4cm My boyfriend thinks it may have come from the Black Hills of South Dakota.

[2 Bar A]

#105 three more views

[keldjarn]

No 5 is large Pyrite crystals and smaller silvery crystals of Galena partly overgrown with crystals of Calcite.
No 72 is light coloured Sphalerite and silvery Galena.
The last specimen is Chalcopyrite with a colourful surface tarnish.
Knut

[2 Bar A]

This next one looks like some kind of mica...measuring 5.5cmX7cmX2cm

[2 Bar A]

More green mica shots

[2 Bar A]

And the next one looks like pyrites with black crystals...measuring 6.5cmX6cmx4cm

[keldjarn]

The first one is either Muscovite (brittle) or Clinochlore ( flexible blades). The second one is Sphalerite with Pyrite.
Knut