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Identity HelpHelp with unusual Termination

3rd Nov 2019 19:42 UTCAura Shop

Can anyone explain what happened to the termination on these quartz crystals?  How does a single crystal result in multiple terminations? The Quartz specimen is from Colombia, and I was informed that it has Cookeite and/or Halloyite inclusions. 
Thank You

3rd Nov 2019 21:33 UTCBob Harman

While I am not an expert in these discussions, I favor the quartz being old, corroded with iron staining near the termination. I am not sure there are multiple complex terminations in the first place; maybe just a simply corroded crystal face and simple termination??   CHEERS.....BOB

3rd Nov 2019 21:41 UTCDon Saathoff Expert

Agree with Bob.....naturally etched by later corrosive fluids.


3rd Nov 2019 22:00 UTCKyle Bayliff

I can't speak to the identity of the inclusions, but the termination on your crystal could be from interrupted growth (i.e. it may have been growing in a pocket, and when it grew into a wall or obstacle, it continued to grow around it. If the obstacle was removed after growth had ceased, it would leave rough holes and gaps like the end of your crystal) or alternatively, intergrowth of multiple crystals can result in multiple terminations (but they're usually cleaner than what your picture shows if that's the only factor at play). It's also possible that your crystal has been damaged. Included crystals have more defects that can allow stress fractures to propagate, and the terminations especially are more prone to breakage. Natural corrosion as the others have mentioned is also a possibility.

4th Nov 2019 21:47 UTCIan Nicastro

If you want more info about the inclusions, I suggest getting in touch with David Ziga, he has been a big proponent of that material which I believe was being called 'Mango Quartz' by some folks. An article on it was in Rocks and Minerals magazine. Your piece seems to match photos of other pieces. 

4th Nov 2019 22:00 UTCBob Harman

Sorry IAN, but as I and DAVID ZIGA have been acquaintances for some time, the appearance is not the same. The color in this quartz specimen almost certainly has nothing to do with the yellow quartz tip inclusions in his Colombian specimens and those discussed in the recent Rocks and Minerals article.     CHEERS.....BOB 
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