I'm STILL looking for a quartz wedge that I can afford - a new one is WAY out of my price range. A three- or four-order wedge would be wonderful. Even trade would be great!! We have several large old slabs of Kelly smithsonite, many unknowns REE minerals from the Rode pegmatite in Llano, TX. Just to name a couple of things..... The 'scope is a Zeiss student model and takes a standard DIN plate.. HELP!!! Don http://www.mindat.org/forum.php?read,100,258761,258761#msg-258761 Wed, 22 May 2013 15:30:41 +0000 Phorum 5.2.15a http://www.mindat.org/forum.php?read,100,258761,263798#msg-263798 http://www.mindat.org/forum.php?read,100,258761,263798#msg-263798 Gerald Wells Analytical Techniques Sat, 16 Jun 2012 02:06:07 +0000 http://www.mindat.org/forum.php?read,100,258761,259314#msg-259314 http://www.mindat.org/forum.php?read,100,258761,259314#msg-259314 Don Saathoff Analytical Techniques Fri, 27 Apr 2012 18:43:56 +0000 http://www.mindat.org/forum.php?read,100,258761,259299#msg-259299 http://www.mindat.org/forum.php?read,100,258761,259299#msg-259299 Donald Peck Analytical Techniques Fri, 27 Apr 2012 15:10:43 +0000 http://www.mindat.org/forum.php?read,100,258761,259248#msg-259248 http://www.mindat.org/forum.php?read,100,258761,259248#msg-259248 When studying the optical characteristics of a non-opaque mineral with a polarizing microscope there are two accessory plates used to aid in determining optical sign (+/-)....among other things. One is the Gypsum Plate which has a fixed retardation and the other is the Quartz Wedge which has a "variable" retardation.

For a better explanation Google "Optical Mineralogy"......there is no quick & easy way to describe it's use....(sorry!!)

Don S.]]> Don Saathoff Analytical Techniques Thu, 26 Apr 2012 23:00:40 +0000 http://www.mindat.org/forum.php?read,100,258761,259237#msg-259237 http://www.mindat.org/forum.php?read,100,258761,259237#msg-259237 gary moldovany Analytical Techniques Thu, 26 Apr 2012 20:58:46 +0000 http://www.mindat.org/forum.php?read,100,258761,259217#msg-259217 http://www.mindat.org/forum.php?read,100,258761,259217#msg-259217
Don]]> Don Saathoff Analytical Techniques Thu, 26 Apr 2012 16:49:43 +0000 http://www.mindat.org/forum.php?read,100,258761,259207#msg-259207 http://www.mindat.org/forum.php?read,100,258761,259207#msg-259207 Donald Peck Analytical Techniques Thu, 26 Apr 2012 15:11:45 +0000 http://www.mindat.org/forum.php?read,100,258761,258998#msg-258998 http://www.mindat.org/forum.php?read,100,258761,258998#msg-258998
Don]]> Don Saathoff Analytical Techniques Tue, 24 Apr 2012 23:30:59 +0000 http://www.mindat.org/forum.php?read,100,258761,258987#msg-258987 http://www.mindat.org/forum.php?read,100,258761,258987#msg-258987 Some years ago I made a wedge. I had a large block of clear quartz that I cut a oriented slab out of and went to one of our local club faceters and had him grind it for me on my direction. It turned out perfect 4 orders but I suspect that was 1 % "knowing what I was doing" and 99% "beginners luck". As I remember, I used Canada Balsam on a regular microscope slide.
Good luck,
Charles]]> Charles Creekmur Analytical Techniques Tue, 24 Apr 2012 21:32:23 +0000 http://www.mindat.org/forum.php?read,100,258761,258986#msg-258986 http://www.mindat.org/forum.php?read,100,258761,258986#msg-258986
Try Hyxtal (http://www.hxtal.co.uk/) its the epoxy of choice for those skilled jewelers who make composite gems. A chat with them may help you settle the grade you want for this application.]]> Owen Lewis (2) Analytical Techniques Tue, 24 Apr 2012 21:04:25 +0000 http://www.mindat.org/forum.php?read,100,258761,258960#msg-258960 http://www.mindat.org/forum.php?read,100,258761,258960#msg-258960
The difficulty with the acryllic is the optical quality - it would have to be used on the stage....

And, yes, hand-lapping a thin section is an art I haven't mastered either!!!!

Don]]> Don Saathoff Analytical Techniques Tue, 24 Apr 2012 17:05:24 +0000 http://www.mindat.org/forum.php?read,100,258761,258940#msg-258940 http://www.mindat.org/forum.php?read,100,258761,258940#msg-258940 Donald Peck Analytical Techniques Tue, 24 Apr 2012 13:37:17 +0000 http://www.mindat.org/forum.php?read,100,258761,258782#msg-258782 http://www.mindat.org/forum.php?read,100,258761,258782#msg-258782
Don]]> Don Saathoff Analytical Techniques Sun, 22 Apr 2012 23:47:32 +0000 http://www.mindat.org/forum.php?read,100,258761,258770#msg-258770 http://www.mindat.org/forum.php?read,100,258761,258770#msg-258770
There is a short description of how to make optical wedges out of stretched acrylic plastic in:

Am. Min. 67:853 1982
Taggart, K. C.
Inexpensive "Quartz Wedges"

Might take a few tries, but would certainly be cheaper than a real quartz wedge.]]> Henry Barwood Analytical Techniques Sun, 22 Apr 2012 22:00:10 +0000 http://www.mindat.org/forum.php?read,100,258761,258761#msg-258761 http://www.mindat.org/forum.php?read,100,258761,258761#msg-258761
The 'scope is a Zeiss student model and takes a standard DIN plate..

HELP!!!

Don]]> Don Saathoff Analytical Techniques Sun, 22 Apr 2012 21:00:54 +0000