Edited and Published by Hale Sweeny
Web Site:
Associate Editors: Geo. Butts, JR Shroeder, Steve Henegar
and Margaret Malm

This list digest contains the following message subjects:

1. LapDigest News for Issue No. 263 - Fri 3/3/2000
2. NEW: Book on Final Polishing?
3. NEW: Need Suggestions for Wheel Selections
4. RE: Diamond Compounds for Polishing Agates
5. NEW: Changing Smokey Quartz into Citrine
6. NEW: What is KEYSTONE Pricing?
7. NEW: Cleaning Emerald Rough?
8. NEW: Plano Molding Company
9. RE: Bubblets in Doublets
10. RE: Help Me Buy a Titan
11. RE: Mineral Oil as a Cutting Lubricant
12. RE: Need Advice on Polishing Amber
13. RE: Need Advice on Polishing Amber
14. RE: BIO: Tiffiny Leitenberger
15. RE: BIO: Tiffiny Leitenberger
16. BIO: Ron Bender
17. RE: Colors of Brazilian Rutile Quartz


Subject: LapDigest News for Issue No. 263 - Fri 3/3/2000

Well, we have a few new members and I want to WELCOME them.
Read a few issues to get the hang of how we work together;
then join in. We have about 2085 members and put out the
Digest about twice a week; each issue has about 17 items,
so that is 34 items a week - not nearly enough for the
number of members we have. So if you send in an item and
it doesn't get published, understand that items which fit
our objectives are used first, and then others are included
if we have room. We focus on methods and procedures for
making lapidary items. Faceting methods questions are best
referred to one of the faceting mail lists.

I am glad you are with us .. from now on, you are part of
"us"! Oh, one more thing -- if I refer to 'you guys', I'm
not being sexist -- I mean everyone!! All of us!!

And look at our website at . Each
past issue is there, and easily copied by opening and using
your 'select all' and 'copy' commands, and then pasting to
a notepad in your computer. There is also a search engine
for searching all past issues based on keywords!

Now about copyrights .. Copyrights for things submitted to
the Digest belong to the authors, except that the act of
submitting them automatically gives permission for their
non-commercial use by, for example, gem and mineral clubs.

I hope you will enjoy your Lapidary Digest experience; if
you have a lapidary specialty out of the ordinary, and if
you would like to write about it, please let me know about
it! We want to start a new list of 'mentor' members who
have special expertise in certain areas.

Spring is coming; my weeping Japanese cherry tree has
budded out and the buds are just bursting to open. It is a
beautiful time of the year. Enjoy it with those you love.
And remember, having fun together builds memories AND a
stronger relationship.

Love stronger, live longer!!


Subject: NEW: Book on Final Polishing?

I have been involved in the lapidary arts for a number of
years, and have never found a really comprehensive book on
final polishing on cabs. I.E.: medium, material, speed, etc.

If anyone is aware of one, please let me know.
Just a reminder. We have a very complete list of lapidary
books available in the Archives -- I think it lists some
280 books on this topic! hale

Subject: NEW: Need Suggestions for Wheel Selections

How do all.

I currently have a pair of arbors, both are combo machines.
One is a Lortone lu6x and the other a home brew unit. I
am currently running a 1-1/2" x 6" 100 grit diamond wheel,
2-1/2" x 6" expanding drum which I normally load up with
either a 400 or 600 grit belt, and finally a leather pad on
the end charged with Raybrite A.

On my home-brew unit, I have a pair of Crystalite domed
wheels, which I am not fond of at all.

I would like to get recommendations on a good set-up for my
arbors. I would like to move to all diamond, but the cost
of the various wheels, belts, etc. is quite high. I would
prefer to listen first to the experience's of others before
going out and buying the wrong wheel or belts. :)

I would like to set up my home-brew unit as a trimming and
roughing workstation. It has a trim saw on one side, and
room for one wheel on the other. The 100 grit diamond wheel
I have now can be quite aggressive on anything and really
makes short work of making big rocks small.

This leaves me room to mount 3 wheels on the Lortone unit.
Question now is which manufacturer do I buy, what shape
wheel, soft/hard backing, etc., etc., etc.

Thanks for any help you all might be able to give.



Subject: RE: Diamond Compounds for Polishing Agates

In LD#261 msg-5, Rebecca Solon asked:

<<Has anyone out there had any experience using diamond
compounds for pre polishing and finishing? How about
cabbing? What should I use to mix with the diamond powder
for an optimal viscosity?>>

By coincidence in the same issue I wrote <msg8> about the
"tight belt" problem I was having with the use of diamond
compound on chargeable belts. I will share my methods here
in hopes of being helpful. I would ask anyone doing
parallel work to please chime in with their views and
techniques. Refer also to LD#250-5 and LD#252-8.

What this is all about is getting a high polish for low cost
investment. The materials I use are: Crystalite 3x8inch
Crystalbelts" at $14.25 for a pkg. of three and Crystalite
diamond compound at $11.25 for 5gm. For each polishing belt
I use 1.5gm to make a cost of just over $8 per grit+belt.
These costs may vary with dealer markup and could be even
lower, unbeknownst to me. There are other brands, equal in
quality, I'm sure... I just haven't gotten around to them
yet. Anyway, compared with $150-$200 per wheel for fixed
diamond impregnated wheels, they're "throw away"! For the
record, I buy Crystalite products at retail through Mark
Abbott Designs in Columbus, Ohio (

Many wheels are too large and the belts are very difficult
to mount and remove! That problem seems to be solved as I
report in LD#261-8:"Expanding Wheel, Belt Too Tight". Dick
Friesen, in LD#251-7, mentioned his problem with belts on
Raytech drums as being too loose. I agree they are
"somewhat" loose but not so much to be a hindrance for me.
How loose? A pencil can fit snugly between the belt and
drum at rest. On startup, yes, there is a tendency for the
belt to "walk". I have a twin wheel setup and made two
guides from a section of 2x4 with nylon tabs that keep the
belts centered for a few turns as it starts. At our club
shop, folks nudge at the side of the belt with the dop stick
handle as it starts to turn. Around 400rpm the belt is
locked on and the wheel gives a soft, easily depressed fit
to the pressing cab. By 1725rpm, the wheel is quite firm.
I like to run about 1500rpm... more firm than soft. I
never have had a belt walk under pressure, even at speeds as
low as 400rpm.

Our club has several wheels that are too big and Steve
Ramsdell in LD#251, msg-8 filed an oversize wheel down. I
haven't tried that because of the warnings about running an
expandable wheel without a belt. At $55 each for expandable
drums, I sure don't like the idea of throwing these
oversized ones away!

To load diamond compound on the belt you will need for each
mesh: a small mixing cup, a disposable dauber, some
"official" silicone extender oil or pure baby oil and a
small amount of lacquer thinner (or Acetone or MEK). Don't
work on a varnished or painted table top with this solvent

For the dauber, a 3" piece of pipe cleaner (fat, fuzzy,
craft store variety) will do. Make a half-inch bend at one
end. A cheapo water color brush works but must be dedicated
forever to a single mesh. Don't use a Q-tip because it
soaks up and retains the diamond mix. Some means is needed
to suspend the belt a couple of inches from the table top
while being "painted". A wire coat hanger can be shaped

Extrude 1.5 grams of compound into the dish. Cover with
(about) an equal volume of oil. A bit more oil than less is
best but not too much more. Mix with the dauber. Dilute
this mixture with about a tablespoon of Lacquer Thinner (not
paint thinner) or MEK or Acetone. Blend well. This uses
just a small amount of flammable solvent but keep any open
flame out of the area!

Paint the belt as completely as possible. Don't try to be
neat and precise. Just smear the material over "all" the
belt. Pay attention to the belt edges where Much polishing
will be done. Just let it be an easy job without too much
fuss, zigzagging around the belt, covering where you miss.
The diamond grit settles out rapidly in the cup so keep it
stirred. Continue until the mixture is used up then let the
belt hang to dry out until there's no more solvent smell
left. Next, the oily diamond coating must be embedded into
the belt composition.

When dry, put the belt on the wheel and crank it up. If
there is a speed control, set at a lower setting. Using a
smooth, fist size, stone press on the turning belt. You
want to "marry" (embed) the diamond into the composition as
it runs. The burnishing stone should be hard and rounded.
After a bit, you can let it build up some heat and work it
back and forth across the moving belt face to even out the
coverage as much as you can. When you get bored doing this,
you are done.

The six polishing grades I use are: 600, 1200, 3000, 8000,
14000 and 100000. In general, the very best polish will be
to use them all... but it also depends on the type of stone
you are working. Flint and Jasper are examples which
respond well to ALL grades in succession. The agate
"family" is more variable and it just depends. More is
better. Unlike cerium on leather which tears the face out
of jade, I haven't found anything bad about using any of the
diamond grades. Some things seem to polish out as well as
they are going to at, typically, 8000 mesh and don't seem
to get brighter with finer mesh. These rocks tend to be on
the softer side. Don't expect to "see" a physical change
from mesh to mesh. Look for the cleaned cab reflections to
become more like the oily surface.

I haven't found the "sanding grade" diamond compounds, those
below 600 mesh, to be worthwhile. Even the SiC cheapo belts
with their "walking" mesh size work very well for sanding.
Also, there are some really great, non-SiC, grits available
at 220, 320, 400 and 600 mesh. The break is at 600 and
finer mesh.

Actually, I use a 600 mesh plated "sanding" belt as the last
forming stage before shifting to 600 mesh diamond polishing.
Don't be fooled by thinking "600" mesh works equally in all
places- a metal plated 600 can sand a flat on a flint cab
real fast while neither the 600 diamond polyester belt nor
the 600 mesh compound described here will do so.

Since no water is used, heat is quickly generated. At the
higher rpm, especially under a heavy hand, the stone gets
Hot! in a hurry... enough that the stone may start to shift
if dop wax is used to mount the stone. But then, polishing
is rapid, needing no more than 15 to 45 seconds or so per

Cleaning the oil off the cab between grits is CRITICAL to
prevent cross contamination! You can't see or feel the
diamonds. The oil is the only clue where they are. If you
get coarse grit on a finer grit belt, it's cooked! Also,
because of the oil, you can't see the polish develop. All
rocks look good coated with oil. I work several cabs as a
group, say 15 to 25 and give them all a "what for" and then
clean them. I wipe with lacquer thinner (on paper towel)
but in the club shop, a good soap and water wash alone does
the job. I cull the set for any needing more work and cycle
this way until all are done for that mesh. Leaving the one
belt on that wheel, I shift to the next finer grit on the
second wheel. If I discover I goofed and need to back up
one grit, it's still on the arbor and I can re polish down
a grade.

Lifespan? I wear the belts out before the grit is gone.
You can start to see the fabric base showing at the belt
joint but it still polishes just fine. I have accidentally
scraped diamond off when my attack angle with a sharp top
edge got too shallow to the down-moving belt. But, for a
couple of bucks in diamond compound the "sinking skiving"
feeling isn't as bad as seeing the resin nubbins fly off a
$120 diamond belt or a $160 Nova wheel. Just use care and
common sense.

Many workers think they have to jump from SiC 600 to cerium
(or tin or chromium) oxides on hide or felt or the like.
There's an enormous difference when these intermediate
polishing stages intervene.

Now, here's for another day- What do the facetors swear by
that the cabbers can't afford (beside diamond).. how about
the classy grades of Alumina like the Reynolds polishes...
or how about Linde-A? Will all of these load these belts
like the diamond compound? When/where will any of these
out-perform diamond. How about the oxides, themselves.
Will they likewise load?

...George Butts


Subject: NEW: Changing Smokey Quartz into Citrine

Hi Everyone:

I had some smokey quartz - a piece about 2-1/2" x 3" and
wanting to turn it into citrine I put it into the toaster
and let it cook quite a while. I succeeded in getting it to
go to the clear quartz phase but it took so long to get to
the yellow phase that I chickened out and pulled the plug
(fears of burning up the wires -- not a good idea when
you're a renter)

So my question is -- can I finish the job in my oven ? And
if so how? And at what temperature?

Thanks a lot

Subject: NEW: What is KEYSTONE Pricing?

{This topic is strictly not part of what we usually use,
but the topic is so pertinent for beginners that I thought
some of the 'old timers' might want to help out with an
answer. hale}

Hi Hale:

When I was visiting Quartzsite, I saw that several opal
dealers sold some of their finished stones with what I think
they said were "keyhole, or keystone" based pricing. At
least that is what it sounded like.

They said that they could mark down the stones from the
listed prices but when they were going to Tucson, they would
charge the full price.

Do you know what they were talking about and can you explain
it to me as I suppose I should understand that way of
pricing if I am going to retail cut & polished opals.

Thanks for shedding light on this subject if you can.

Leigh Miller

Subject: NEW: Cleaning Emerald Rough?

Hello all, first post since my Bio a month or so ago.

I've gotten in some beautiful emerald rough, but am at a
loss for how to remove the blackish stuff that is layered
atop my emerald rough. I have been told it's some sort of
char from the mining process. I'm a little worried about
just experimenting, if only because the batch of rough I got
in was just amazing, and I'd hate to lose the stones to my

Any ideas on how to clean emerald rough up? Many thanks!

As someone who delights in collecting gemstones, I have
often found it odd that a truly remarkable jewel will be
honored for it's faceting and it's individual, unique
flaws, while an equally remarkable human will be shunned for
showing other facets of their personality, or for admitting
any flaws. It's a sad commentary on our society that we
treasure the jewels from Mother Nature more than we treasure
the ones we make ourselves.

Subject: NEW: Plano Molding Company

A hearty thanks to Plano Molding Company. Some of us use a
tackle box for tools and supplies when we do shows or in
my case, when we take classes. My Plano tackle box broke a
hinge bracket after a lot of tough use. A call to Plano on
their 800 number to try and buy a replacement bracket
brought two each of the two types and rivets and
instructions to effect the repairs at no charge.

Talk about responsible people!

Bill Eisenenberg
Vista California

Subject: RE: Bubblets in Doublets

Roger Pabian said:

<<I have ... an unusual problem with bubbles forming in
doublets long after the doublet has been (made. Made from)
.. translucent agate with black sagenitic inclusions. ..
(snip).. In several weeks after the doublet is finished,
small bubbles begin to form in the cement only in the space
between the quartz cap and the sagenitic inclusions. In a
few days time, the sagenitic area is covered with a mist of
tiny bubbles and the rest of area in the doublet remains

I've tried several different kinds of cements, epoxies,
etc., ...tried to neutralize the sagenitic area and have
tried sealing it separately before making the doublet.
Regardless ..., about a month later, the sagenitic area is
covered with bubbles. Has anybody in Lapidary Digest Land
ever encountered this problem and, if so, has anybody come
upon a solution. This is some very attractive sagenitic
agate but it remains unusable because of the ... bubbling.

Apparently some chemical reaction that I can't seem to
check is taking place. >>

Roger, Hale, and list...

Without knowing what the inclusions are, and what specific
epoxy chemicals are being used, I can only speculate on
chemistry. But a few ideas do come to mind.

First, the inclusions might be absorbing the solvents in
the epoxy and later releasing them. Alternately, the
inclusions may be acting as a catalyst (or reactant),
either during curing, or afterwards, to cause the breakdown
of the epoxy.

The obvious solution is to try another 'glue'. Have you
tried Balsam?

Kreigh Tomaszewski
Please visit our family web pages at
Roger, I don't know what a sagenitic inclusion is. Would you
tell me about it? Before glueing on the cap, were the
inclusions exposed or still totally encased in agate? hale


Subject: RE: Help Me Buy a Titan

(In the last issue, Andy Parker asked for help in getting a
Titan from the States. I told him that if he didn't get
any other offers, I'd help him with it. This is his reply.)

Hi Hale

I have had over 30 offers - some before I read my copy of
the Digest. I have replied to everybody and once I work out
what I am doing will write again.

We certainly have a great bunch on this list.

Take care
Andy: They ARE the GREATEST!!! hale

Subject: RE: Mineral Oil as a Cutting Lubricant

Hi Hale,

As regards using mineral oil in cutting saws, I agree in
general that it is probably as good as the petroleum based
cutting oils. Especially for people who are sensitive or
allergic to such. Our shop used the Rock-Oil (Roc-Oil?)
from Diamond Pacific for nearly a year. The one draw back
it has is that it holds the cuttings in suspension for a
very long time. It wasn't unusual to find grit in
suspension more than a week after last use. Our usual
schedule was stepped up to twice normal to compensate. I
don't know if other mineral oils do this.

Our shop boss became convinced that in the long run this
may lead to early retirement of the blades, especially the
larger diameter blades. I think it was a subjective
conclusion but could not offer any opposing facts and we
have switched back to Almag.

There were two students who were specifically sensitive to
the Almag and they have reported some symptoms since we
switched, but I have encouraged them to wear filter masks
and neoprene or nytrile gloves when working with the saws
and they report less symptoms then when they did not use
mask and gloves. They reported no symptoms with the
mineral oil.

Hope this has helped.

Tom Burchard a.k.a. Roxhund
Tom et al: Mineral oil is defined as *: 1. Any oil found in
the rock strata of the earth; specif., petroleum and: 2.
a colorless, tasteless oil derived from petroleum and used
as a laxative. It is a natural product of petroleum
refineries, differing only in where they take this 'cut'.
I don't think there is a tight petroleum definition of
mineral oil, but could easily be wrong! The only biohazard
I know of is that inhaling the OIL into the lungs presents
a danger of chemical pneumonia. hale
*Excerpted from Compton’s Interactive Encyclopedia © 1994,
1995 Compton’s NewMedia, Inc.

Subject: RE: Need Advice on Polishing Amber

Some few years ago - 1982- during a gem show in Charlotte,
a dealer friend I was helping was approached by a lady with
a piece of amber she had immersed in some kind of cleaner
and of course the entire finish was gone. Being at a show
with no equipment, I borrowed a little (1/8th teaspoon) of
Cerium Oxide and with a piece of damp leather and a very
small sprinkling of the cerium and using a lot of elbow
grease, brought back the polish.

Use something like others have said, Suede, Denim, soft
leather; just a little dampening and a little - very little
- cerium, tin, aluminum oxide and a bit of hard pressure
and it will polish.

heat will soften or even melt the amber. After all - it is
just resin.

Good Luck


Subject: RE: Need Advice on Polishing Amber

I just replied to a reader last month who I have polished
amber in the past, but now the list has grown too much with
the same question "How do I polish Amber"

After you have pre-polished your amber to the desired shape
adhere a plain leather disk on your lap. With your amber in
one hand and a squirt bottle full of water in the other,
sprat the lap generously and continue to do so as you rotate
your amber. Just remember to keep the leather wet (not
dripping wet) at all times (experiment with the RPM's to
see what gives you best results.)

John Ratcliffe
Kamloops, BC

Subject: RE: BIO: Tiffiny Leitenberger

Tiffiny Leitenberger ( to say:

<<..(snip).. I just got a Dremel and I expect to be able
to polish some of my rough opal. I've done a little
research on the process, but if anyone can give me more
info, I'll be much obliged. I'm afraid to start on a
stone, because I think I am going to ruin it!!! Someday I
hope to get some decent equipment and be able to make
cameos out of opal.>>


I'm an opal lover, too, and have cut quite a bit. There's
nothing quite like the thrill of "opening" a piece of opal
and finding the rainbow inside. You can get good results
with a Dremel-type tool and patience, but one thing scares

We've had several discussions about this on the Lapidary
Digest, and the people at Dremel have said it's not safe to
use their tools around water. [See note below.] Since all
stones should be ground wet (to control dust and save the
grinding tools), especially heat-sensitive stones like opal,
you'll need to keep the stone wet. Either dip it in water
and then touch the sander to it briefly, or work it
underwater. I'm afraid of you hurting yourself with a

All of the opal carvers I know of, or have read of, use a
Foredom-type tool. With these, the motor is far from the
water and the handpiece is the only thing that can get wet.
It's what I use.

I suppose if you have a battery-operated tool that the
voltages would not be quite as hazardous as using a plug-in
tool, but I'd still try to get Foredom type tool. Used ones
can be found for under $200. There are other manufacturers
that sell new for under $100. You can probably get diamond
carving bits from your dentist, if you tell him what you're
going to use them for. My dentist offered to sterilize a
bunch of old diamond bits for me as soon as I mentioned I
was a lapidary.

If you need more information, feel free to write me directly
rather than using the digest.

Hope this helps,


Bob Lombardi W4ATM in Melbourne, FL (ex-WB4EHS) or or
Visit ATM's Resource List at or
Visit me at

Subject: RE: BIO: Tiffiny Leitenberger

Hi Hale -

Saw Tiffany's BIO in your #261 Digest. I love opal also
and have a bunch of Mexican with pockets and some beginner
grade white. If Tiffiny wants, I can send you a small box
with a couple of ounces to pass along to her. That way she
can practice to her hearts content. Also believe I still
have a copy of my teaching guide that I used when I taught
cabbing at the Patuxent Lapidary Guild over at Ft Meade, MD.

Mike Hakulin Sr
Mike: That is a VERY nice offer and if Tiffany says so, you
can send them to me at 3500 Cambridge, Durham, NC 27707; I
will be glad to high-grade them and send what's left on to
her! -- JUST KIDDING, of course!! (big grin) But I will be
glad to act as intermediary and send them on to her. hale

Subject: BIO: Ron Bender

Hello, I am new to the list although not new to the hobby
as I have been collecting, polishing and admiring rocks
and minerals for over 50 years. I am a 61 year old retired
teacher here in the state of Washington. I have a mineral/
rock collection of about 350 specimens. Mostly self

At the present about all I do is cut slabs of agate or other
transparent or semitransparent material (18" Lortone) and
tumble or hand polish them for inclusion in stained glass
windows. I also collect sea shells and fossils.

Thanks for reading and hope to learn from this list.

OLYMPIA, WA 98506-3623

Subject: RE: Colors of Brazilian Rutile Quartz

Hale asked:
<<But what makes the needles (in rutilated quartz) golden
colored, Jon?>>

Yes! Hale, you have a point.

The colour of rutile in quartz is unusual. But think of
satin spar. It's ordinary gypsum, but has a nice silky
lustre in nearly silvery needles. Much the same. Also the
silky green of many tremolites stands out compared to the
ordinary blackish green of bigger crystals.

I have always thought of the color in the rutile needles as
light reflections in striation of the crystal surfaces.
Whether it's from the front or from within the rutile
needles. Striation is a habit of rutile, that you also see
in bigger crystals.

But this is just my theory. I know nothing for sure of

Maybe we could compare with sugarmass for drops, that has
been drawn several times to mix colour and flavour even.
It's silvery too. But that's because of several airbubbles
trapped in the mass, and drawn with it.

The same reason that rainbow-, gold- and silver obsidians
shine. And some of the tourmaline-cats eyes too.

Never the less. Quartz in any aspect is a fine gem/gemmy


Jón Olaf Svane/Denmark

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