LAPIDARY DIGEST
Administered by Hale Sweeny (hale2@mindspring.com)
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This list digest contains the following message subjects:

1. NEW: Tiger-eye Treatment
2. RE: Stabilizing Turquoise and Opal
3. RE: Stabilizing Turquoise and Opal
4. RE: Stabilizing Turquoise and Opal
5. Re: Tumbled Cabs
6. RE: Polishing Obsidian
7. RE: Polishing Obsidian
8. BIO: Vincent King
9. BIO: Dave Siskin

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<MSG1>
Date: Saturday, June 28, 1997 11:21 PM
From: Lapidry@aol.com

Subject: NEW: Tiger-eye Treatment


I've seen nice catseyes produced from tiger-eye. I understand they use
acid to lighten the tigereye to the light honey color. Oxalic acid might
be the acid. Is someone familiar with the exact process?

Dan
lapidry@aol.com
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<MSG2>
Date: Sun, 29 Jun 1997 04:57:10 -0400
From: mark@LICCINI.com

Subject: RE: Stabilizing Turquoise and Opal


Brad Smith <bsmith@infodial.net> recently asked in Issue #12:

> I've noticed the term "stabilized" used with
> respect to turquoise and certain opals, and I
> assume this is a process of curing flaws
> in a stone so as to be able to shape and polish
> it without getting a lot of cracks and pits.
>
> What are the commonly used stabilization processes?
> Which techniques are used with turquoise?
> Which techniques are used with opal?
> How can one recognize a treated piece?


The term stabilized is most often used when reffering to the process of
hardening Turquoise and like materials which are too crumbly or soft to cut
and polish.The process is done in an autoclave where resins are injected
under heat and pressure.
A similar process is used with the dust of these types of materials to
press it into a cuttable block.The best test is to touch the material with
a hot pin.You can smell the plastic on a treated piece.
More interesting to the small lapidary is the process that I will call
fracture filler.This is actually an intregal part of the lapidary process
when working with Emerald or certain Opals.
First I will mention the commerical product called "Opticon" Which is a two
step filler which seems to be like an epoxy and water Glass mix.This is a
often used filler manufacutured by Huges Associates,Excelcior,Minn that
you will find in all Lapidary supplys
Now Epoxys you will find very useful as fillers of small pits or
cracks,and most effective to use as a backing to stabilize a fragile piece
throught the sawing and grinding process. Best for this is that gray plumbers
epoxy applied accross the back of the slab.
Water glass is a good penetrant and sealer. This is very good to hide
internal flaws. It is just as effective as oil to show color and hide the
flaws, except more stable as it actually sets up like a glue.
Lastly I want to mention Canadian Balsam,which you will find very useful
as a fracture filler. Pure Balsam is a little complicated in the
application,as one needs a vacuum/pressure & heating unit to apply.This can
be homemade with parts under $100 (excluding compressor).I am testing now a
variation of just Balsam sold to apply slide covers called "Paramount".This
is Balsam thinned with Toulene,and with chemical additives to stop the
yellowing that can occur with time and the growth that can appear also with
time as Balsam is an organic substance.
There is a lot more of these types of "mother nature" fixers.But these
above are the easiest to obtain,non toxic and quite effective

Mark Liccini

LICCINI
Gemstone Rough Dealers since 1970 U.S.MAIL
E-Mail: mark@LICCINI.com 107 C.Columbus Dr.#1A
http://www.LICCINI.com Jersey City,N.J.07302
Voice Mail/Fax: 201-333-6332
======================================

<MSG3>
Date: Sun, 29 Jun 1997 06:36:48 -0400 (EDT)
From: Vybtl@aol.com

Subject: RE: Stabilizing Turquoise and Opal


Greetings Friends:

Most common method I'm aware of is using a 311 (two part) epoxy and acetone
mixture. Brains foggy on the exact brew, seems as though it's one, two part
tube 311 epoxy to one quart of acetone. Mix it up in a glass jar, place
material to be stabilized inside, seal, and forget about it for a month or
so. KEEP IT SEALED! And in an area that's cooler than my back yard during
the month of July. Places NOT to keep it; near the water heater or other
sources of heat that could emit either sparks or open flames (acetone is very
combustable), where the children can find it, if you're still blessed to
have them in the house. "Daddy! Look at these beautiful blue rocks I found
in this jar!", goo dripping from their fingers, on the wife's carpet, trailed
through the kitchen. Trust me, no one's going to be happy at this point!

Providing they survived the month long journey (or longer if your memory is
like mine [four months later] "What's this?!" [notice hint of irritation in
voice]), remove stones from soup. (Kitty litter scooper works good as long
as the mouth of the jar is wide enough, and it's not currently being used for
it's designed task.) If the seal is good on the jar, the liquid will last a
very long time, through many soaks, unless the child analogy comes to bear.
Place extracted stones on a surface that no one's going to mind if it gets a
little crudded up (wife's china, DON'T DO IT!). Let dry another week, have
fun!

Why stabilize? Seen many an awesome turquoise gem that was full of cracks,
pits and the like. As long as it will polish, and it's turquoise, it's a
gem. Problem is, most material on the market is to soft to cut, thereby
won't take a polish. The Stabilizers harden the material enough to allow the
Zam to do it's job. One of the beauties of turquoise, no one cares if it's
calibrated, or if there's rough spots in the stone, or if one can't comb
their hair in the reflection of the polish.

How does one tell if it's been stabilized? Rough form: Plastic like
substance surrounding the stone, easy. Cut form: Not so easy. A raw
turquoise nugget will tug at your lip when you kiss it. This property is
deminished when stabilized. Most cutters don't polish the backside of the
stone, freak 'em out, give the stone a kiss on the back side. If you feel an
appreciable tug, probably not been stabilized. Light pull means more than
likely stabilized. Should this happen to you, look them in the eye and say
"stabilized". Walk away. Watch them from a distance. See if they don't do
the same thing! I love gem shows! It can be so entertaining! Polished
areas don't give the same effect, so if the stone is also polished on the
back side, your guess is better than mine. Off topic slightly. Chrysocolla
will do the same thing, except it will try to rip your lips off your face.
Difference between the two stones? Duct and scotch tape.

Sorry for getting long winded, Hope this helps some.

Vincent
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<MSG4>
Date: Sun, 29 Jun 1997 09:43:14 -0700 (PDT)
From: drewid@lanminds.com

Subject: RE: Stabilizing Turquoise and Opal

I'm not familiar with stabilized opal, but the process for turquoise is
designed to remedy its tendency to be porous and change color over time. It
usually involves impregnation with polyester resin, with or without vacuum
assist. Often a dye is introduced as well- this can sometimes be recognized
by its overly blue color. One can generally smell the polyester when
cutting the stone; I'm not sure how to non-destructively test for
stabilization in a stone that's been set. I've heard that the very finest
grades of turquoise don't need stabilization, but most of the material I've
worked with (even the expensive stuff) seems to have been treated this
way.


Andrew Werby - United Artworks
Sculpture, Jewelry, and Other Art Stuff
http://users.lanminds.com/~drewid
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<MSG5>
Date: Sun, 29 Jun 1997 06:36:50 -0400 (EDT)
From: Vybtl@aol.com

Subject: Re: Tumbled Cabs


Hi Mark, et al:

<<Ok, now for the dumb question of the week.>>

No such thing in my book.

<<I have been told by some lapidary people that they preform their cabs,
..[snip]... camp director.

Mark Case
Randleman, NC
MarkCase@aol.com>>

Preform your cabs on 100 grit if you like. Want a dome in the stone, better
put one in. Don't mind the flat lapped look, don't. I use a vibratory
tumbler when doing a larger quantity of cabs. Rough out the shape, put a
dome on it, fire up the tumbler. 320 grit for a day or two. Clean them off
and look at them. Do they have the same texture over the entire stone? Go
to 600, if not, give them another day in the 320, or till they smooth out.
Not so long though that they go wafer thin though. Going between grits, two
suggestions. After rinsing off the stones and dumping the sudge from the
hopper, run these through a rinse cycle for about 6-8 hours, about 1/2 full
of water. Helps loosen grit and remove clay like substance from the surface.
Then scrub cabs with a tooth brush to ensure all grit has been removed. Go
on to next grit, using same cleanup proceedure. After 600 grit, with the
vibratory at least, you can go on to the polish. If possible, and it's
highly recomended, use different hopper for each grit and polish, lessening
the chances of cross contamination, and much consternation when you pop the
top! Did this help any?

Hope so

Vincent
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<MSG6>
Date: Sun, 29 Jun 1997 08:09:51 -0400
From: daves@sunline.net

Subject: RE: Polishing Obsidian


For Obsidian, I like to use Cerium Oxide for the final polish. It will
bring up a super high polish.

The cloudiness you are referring to may be a poor polish, or it just might
be the obsidian itself. Obsidian seems to show every fingerprint and
smudge. Try wiping your finished stone and look at it without touching it
with your fingers. If it is still cloudy, then it is a polish problem.

Dave
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<MSG7>
Date: Sun, 29 Jun 1997 13:12:23 -0400
From: jo7ma4@mail4.voicenet.com

Subject: RE: Polishing Obsidian


Trish,

I do not know if you would call this a trick or not, but I have found
obsidian like jade seems to polish better if you follow the flow lines. I
found that polishing in only on direction seems to make all the difference.
That and allowing the stone to get hot (without coming off the dop). I have
polished using 100,000 and in some cases 250.00 diamond grease on REZ belts
with great success.

Mack Lingenfelter
Springfield Pa.
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<MSG8>
Date: Sun, 29 Jun 1997 06:36:35 -0400 (EDT)
From: Vybtl@aol.com

Subject: BIO: Vincent King


Greetings fellow cutters:
With the test of this wonderful resource now firmly behind us, let the fun
begin. My name is Vincent King, father of three beautiful daughters (not yet
full fledged Rock Puppies, but they're coming along nicely), and husband to
the best friend a man could ask for, Yvonne. These salutations originate
from the oven door of the Sanoran Desert, Phoenix where the seeds of enjoying
God's gifts were firmly planted. The years spent in enjoying this art is
infantile in duration when compared to you, my many mentors, and to you I
give my thanks for your willingness to share your combined knowledge. (Which
end do I dop to, again?)

Currently unaffiliated with any Society or Lapidary Organization, intentions
and desires are high to join in the Maricopa Lapidary Society. As the
nastiest of the three letter words is currently being prohibitive to
attending the meetings, there is hope that this will change in the very near
future, allowing both the ability to provide for the family during normal
hours, and meet with those who share a common interest. Currently, I am
involved in three endeavors that relate to the gem cutter, King/Rabbitt
Enterprises with Fischerstone, VYKing International Cyberstones, and a
limited affiliation with Apache Gems (Built and run the website). These
later two won't be discussed on this list as I am sure that Hale will c--sor
me. What limited knowledge garnered through the years, I humbly present, and
that provided, I eagerly devour. Thank You all, even you Hale!

Vincent
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<MSG9>
Date: Sun, 29 Jun 1997 08:03:53 -0400
From: daves@sunline.net

Subject: BIO: Dave Siskin


Hello!

I have been involved with rocks and lapidary for about 15 years. I am a
Graduate Gemologist and a professional lapidary. Most of what I do is
repair work on gemstones, including faceting, inlay and special cuts
(concave facets etc). My real specialty is opals, but I will cut anything
except diamonds. I use a Diamond Pacific Titan for most of my non-facet
work and Facetron for facetting.
I have owned a gem and mineral gallery and been involved with wholesale
minerals at shows including Tucson and Quartzite.

I look forward to learning more through this list and hopefully being able
to add a bit of knowledge.

Dave
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