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extraction of quartz crystals from limestone matrix

Posted by Mark & Linda Mahlum  
extraction of quartz crystals from limestone matrix
October 02, 2009 12:51AM
I have uncovered a quartz pocket with a wall of 6" crystals attached to a limestone matrix. Any suggestions as to how to remove these groups of crystals without shattering them? Power tools are not an option. I plan to use a 3/4" chisel and crack hammer.

Help!

Mark
Re: extraction of quartz crystals from limestone matrix
October 02, 2009 01:34AM
us    
Mark,

I would use a caper and cut a series of holes behind the vug, far enough to carve them a few inches deep, and try and remove as much of the vug in one piece as possible. If you take your time and bring a number of chisels you should be able to "set" a number of chisels, one in each hole you make with the caper. Once these chisels are "set" hit them all, one at a time, with hard blows. If the holes are deep enough, the rock is competent enough and the chisels are evenly hit, the rock should crack between the holes like perforated paper. I have had success over many years doing removals like this.

Good luck and PM me if you want to talk more about it!

Cheers.
Ian Merkel
Re: extraction of quartz crystals from limestone matrix
October 02, 2009 03:07AM
us    
Why not just dissolve the limestone matrix with weak HCL or vinegar?

Frank
Re: extraction of quartz crystals from limestone matrix
October 02, 2009 03:34AM
Franklin,

The wall is a mountain, and on a cliff face. I am lying sideways with my feet hanging over a cliff. The most difficult collecting site I've encountered.It would take a trainload of HCl.

Thanks for the input.

Mark
avatar Re: extraction of quartz crystals from limestone matrix
October 02, 2009 08:37AM
pe    
other than Ian's tip is there really much other way to go about it? The terrain and space makes it difficult. From what you write it sounds isolated and chances of someone stumbling upon these are slim to none. Leaving them for viewing seems silly. Give it a whack and see what happens. Doesn't seem like much to lose. Maybe say a prayer beforehand. Good luck smiling smiley

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A buena hambre no hay pan duro
Re: extraction of quartz crystals from limestone matrix
October 17, 2009 03:45AM
us    
Hope it is not too late to add some details in the chop em out sequence.
I do some extraction work in my area with sphalerites, calcites, fossils and such. I use cheap ducttape that I will cover over the crystal I am working with to protect from dings due to flying debris or the inevitable fumbled/dropped tool. I also use rags/ foam/ anything soft that I can pad the drop off and or brace the piece in place. I like the duct tape for this a lot too as one hand is holding a hammer and the other the chisel and POING- the specimen flys off to a sad landing. The piece of tape is a cover and another piece is an anchor.
I prefer the CHEAP tape as it has enough goo to stick where I want, I don't have to fight it off the roll, and most important, it comes off the specimen much easier without damaging the rock and/or leaving residue. Don't leave it on for too long or you get gooed- most any solvent will fix that though...
Hope that helps- It has saved me some cool specimens!
JohnOsmiling smiley
avatar Re: extraction of quartz crystals from limestone matrix
October 17, 2009 06:50AM
pe    
John, that is an awesome tip! I will have to keep that in mind as so many pieces have been hacked at and ended up in the mine spoils over my shoulders! This also could be useful for hand trimming. Thanks

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
A buena hambre no hay pan duro
Re: extraction of quartz crystals from limestone matrix
October 19, 2009 03:53AM
A friend's Microblaster worked perfectly. It separated the group, intact from the limestone matrix. The hardest part was carrying it down from the cliffs.

Mark
Re: extraction of quartz crystals from limestone matrix
October 19, 2009 04:00AM
us    
Nice to hear Mark!
Re: extraction of quartz crystals from limestone matrix
November 04, 2009 07:19PM
An excellent tool I hope to afford someday...
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