Administered by Hale Sweeny (

This list digest contains the following message subjects:

1. LapDigest News for Issue No. 149 - Thurs 6/25/98
2. NEW: How to Operate a Vibratory Flat Lap
3. RE: Polish for Corundum
4. RE: What Polishing Compounds to Use?
5. RE: Polishing Sapphires
6. RE: What Polishing Compounds to Use?
7. RE: Want Plans or Help in Designing 6" Rock Saw
8. RE: Want Plans or Help in Designing 6" Rock Saw
9. RE: Does Ammonite Occur in US?
10. RE: Vibrator Tumbler for Opals
11. RE: GFI Protection
12. RE: Frosting Black Onyx
13. RE: Frosting Black Onyx
14. RE: Frosting Black Onyx
15. RE: Frosting Black Onyx
16. RE: Using Water with Dremel or Drill
17. RE: Source for Sphere Stands
18. RE: Crystal windows
19. WTB: Used Double Barrel Rotary Tumbler
20. NOTE: Death of Gilbert H. Rowe, Jr.
21. BIO: Linda Johnson
22. BIO: Paul Fanshaw
23. AD: Irons Lapidary Shop
24. WTS: 24" Slabsaw


Subject: LapDigest News for Issue No. 149 - Thurs 6/25/98

HAPPY BIRTHDAY, LAPDIGEST. Forgot to mention it, but one year
and two weeks ago, we sent out the first issue, and we are
now sending out the 149th one. As on this morning, we had
1094 subscribers!!

This is the third Digest issued this week, and I am just
about caught up with the backlog of messages. Hope you have
just about caught up with reading these Digests!

A letter from Dick Friesen on polishing is published below.
It is quite good, and I hope it will elicit many questions
and comments on polishing. Dick published the paper in Rock &
Gem two months ago on polishing jade, and I have asked him to
abstract that paper and publish it here. Let's keep this
thread on polishing going, gang; we have a great start!

Next issue: Channel Work

Stay safe and have fun!


Subject: NEW: How to Operate a Vibratory Flat Lap


I recently acquired a Lortone vibrating lap and it came with
no instructions as to how to use it. It has 3 18" aluminum
pans and the motor base the pans fit onto.

I would like to pre-polish flat surfaces of agates etc. prior
to shaping, preforming and finishing the edges.

I would appreciate any info on how others are using this
machine and their grits and times etc.


Bill Mason
There are several files in the Archives which will give you
answers to most questions; the first one is:
'FlatVibratoryLapping.txt'. You can get it in the usual way
using the GET command. ( Put 'GET FlatVibratoryLapping.txt'
on the subject line and send to If
you are hazy on the way to get files, see the note at the end
of any issue or see the Welcome letter. More lapping info is
in Issues 74, 84 and 85. Their file names are Digest74.txt,
Digest84.txt and Digest85txt. Write if you need help. hale

Subject: RE: Polish for Corundum

Welcome to the Group, Bert. In your Bio, you posed a
question on how to get a bright polish on ruby and
sapphire. I hope someone knowledgeable responds. I
have used the same sequence you indicated (1200 to 8k
to 14k to 50k) with the same apparent results

I'm responding, however, because of a recent article "The
Difference Between Grinding and Polishing" by Gerald L. Wykoff
in the August issue:52-55, 1998, of Rock and Gem. You may
find his article interesting. In the article, Mr. Wykoff
states that if you want a super polish on corundum, it's
usually best to prepolish with 600 and 14,000 diamond
respectively (skipping 1,200 and 3,000 prepolish)-and then
with 100,000 diamond grit or higher as the final step. He
indicates that this is specific to stones of about 9 Mhos

I haven't had a chance to test this myself, perhaps one of
the many other members has some comments?

Subject: RE: What Polishing Compounds to Use?

This is a subject that I find personally interesting and hope
to do a good article on it when I get the time. But in hopes
of getting some more responses and discussion going here are
some of my ideas on the subject.

"Gem and Lapidary Materials" by June Culp Zietner. Available
at some book stores and from the Lapidary Journal. June has
covered most if not all materials you will ever cut and has
recommendations for cutting and polishing them.

Any recommendation for polishing difficult gems need the added
statement that technique is as important as what polishing
compound you select. The techniques are not well described in
any book and in fact I have found many books to be hard to
follow or contradictory. Most books describe techniques for
agate and that is about all. Since agate is about the easiest
material to polish, that is not too helpful.

I think a whole book could be written just about polishing
technique so I won't be too helpful here either. Hopefully
others will send in information on their ideas. We could all
benefit from the experience of others.

The oxides, cerium, tin, and chrome have been used for years
and with patience almost all gem materials have been
successfully polished with them. But newer polishes are
available and in most cases are superior to them.

Colloidal polishes of diamond, alumina, silica, cerium, tin,
and chrome are available from Rick Ford at mAji, Beaver Creek
Oregon. These polishes hold the polish in suspension better
and require less polish and in general are faster then the
standard polishes.

Colloidal silica should be one of the best polishes for lapis
and Rhodocrosite. They should polish better with the high PH.
I have some but I haven't had a chance to compare them enough
yet to say.

There are several different aluminum oxides and they each
have their place. The one you hear about most I think is
Linde A. This is a .3 micron polish that has been around for
a long time and could be listed as an old standby except for
its price, it is about $100 a pound. Reynolds has a set of
polishes available through Diamond Pacific and I have had
very good luck with their .2 micron polish. FitzCorp in Point
Blank Texas has a .1 micron polish that sounds to me like a
very good product (they have a lot of research behind it) but
I have not tried it yet.

Myers Rapid Polish get my vote as the best jade polish I have
tried yet (see my article in the June Rock and Gem). There is
something about its structure that controls orange peel

I find as time goes on I am using aluminum oxides oftener and
the old standbys less. Again technique plays a large part in

This has been the polish of choice for difficult stones for a
long time by a lot of cutters, but I am not one of them. I
think the extender fluid hides the surface too much and I am
taking too long to get the polish I want. I know others use
it and like it and I would like to hear your thoughts on it.

There are several manufactures of diamond polishing belts and
wheels and all do an excellent job on agate. In fact if you
do mostly agate I think the convenience is hard to beat. With
the harder to polish stones I always seem to do better with
one of the other polishes.

Dick Friesen

Subject: RE: Polishing Sapphires

In a BIO in Issue #147, Bert Parks asked how to polish rubies
and sapphires. 50,000 diamond on either a ceramic or cast iron
lap works well if you want to polish facets; cast iron is said
to be faster. I prefer the Al2O3 ceramic, as the facet edges
come out sharper. Bob

Subject: RE: What Polishing Compounds to Use?


I can't remember the name of the Sinkankas book that covered
lapidary cutting and polishing. The info on types of polishes
for each material was clearly put forward. Can you come up
with the name?

Steve Ramsdell

Non-commercial permission to reprint
Yes, Steve; the book I think you are talking about is named
GEM CUTTING and is one of my primary references for things
lapidary. hale

Subject: RE: Want Plans or Help in Designing 6" Rock Saw

In a message dated 6/22/98 2:01:59 PM Eastern Daylight Time,
Craig Nielson wrote:

<<Does anyone have plans for a home made 6" saw.(snip)>>

I might suggest that you look at the Graves Cabmate unit. You
can buy just the arbor which is all cast aluminum for $100.
Then add your own motor and accessories. I made mine with a
nice 2 HP DC Variable speed motor, 0-5000 RPM. The advantage
of the Cabmate is that you can use it to saw, grind, drill,
polish etc. There are a variety of accessories for it. For
$200 total you can have a nice unit. Add an expanding drum
and a saw blade and you're ready to go.

non-commercial republish permission granted

Subject: RE: Want Plans or Help in Designing 6" Rock Saw

Thanks Earl

I like your thinking on the saw. Scary as it sounds I also
have an old 20 MM can here and had never thought about using
it. Sometimes its almost as fun to build the equipment as it
is to cut the rocks.

BTW what do you mean "not much to look at"? To me that's a
work of art!! Grin

Craig Nielson

Subject: RE: Does Ammonite Occur in US?

Hi Hale,

While selling in Texas when we were in business, we catered
to the Rocka Shops, and in Sanderson, Texas, on hwy. 90, west
of Uvalde, east of Alpine, we found Ammonites in the local
Rock Shop. The woman said they were found right around
Sanderson after a flood where the land needed leveling.

We have one of the Ammonites from there. It's been maybe 20
years since we obtained it so I don't know where they stand
with them now.

Barb Langham

Subject: RE: Vibrator Tumbler for Opals

<<I'm an opal cutter in Australia. Most of my stones are cut
by hand but I have a number of free forms that I would like
to tumble in a vibrator.

Does anyone know who supplies the vibrator tumblers that will
fit multiple bowls at the right price.... and can you give
me some advice on the right grits to use. I've been told
that 220, 400, 600 and tin oxide will do the trick.

I have experimented before using these but found the final
polish was difficult to get. It was still quite mat, and
not shiny enough.>>

Dear Peter,
Your initial grit would depend on how rough the surface was.
Unless you have jagged edges, 220 grit is going to drastically
cut into the opal and change the shape. Given a non-pitted
surface and smooth edges you might even just use the 600 grit
before polish.

I used to have a problem with the final polish until a jeweler
friend recommended using Crystalite "A" (can be ordered from
1-800-777-2894 as C5412620, priced at $30 US for 4 ounces).
I've gotten much better results with that than other polishes.
I have no financial interest in the company or product.

Here is a procedure that I was given for vibratory tumblers
with soft stones:

1) Hand mix the stones with an equal volume of fluffed laundry
drier lint. This keeps the stones from banging on one another
and leaving chips to damage the work.

2) Use extreme care between each stage to take just the
stones, then wash them and the bowl carefully. A separate bowl
for each grit is a good idea as well. Discard the lint between

3) Check often, particularly if you are used to rotating
tumblers. Vibratory tumblers work much faster and if you
vibrate too long the grit or polish starts undoing the
progress it had made.

I trust I don't have to tell you not to pour grit down the
drain in less you want to become your local plumber's best

Jerry Mings Home Page

"non-commercial republish permission granted"

Subject: RE: GFI Protection

To encourage any of you out here to get a GFI outlet, I just
had 2 installed by an electrician. It cost me 59$, took 30
minutes or less. Peace of mind is worth it!


Subject: RE: Frosting Black Onyx

<< I have cut some interesting shapes in black onyx and
would like to apply a "frosted" finish to them without using
a sandblaster. <snip> I'm thinking >that there must be some
chemical solution or an acid that will etch the surface of
the stone to give it that frosted look. Maybe whatever it is
that glass artists use to etch window glass?>>

Hydroflouric acid is the glass froster's alternative to sand
blasting, BUT that is some real deadly stuff. Sandblasting
is much safer and cheaper when done by a local glass

Not only is hydroflouric acid downright nasty, but it is
difficult to obtain. Save yourself some grief and check out
local glass suppliers.

Hydrofluoric Acid is not something that you want to be using.
As a chemist, I am speaking from practical experience.

Glass (and other material) etching is normally done with
ammonium bifluoride mixed with a wetting agent. Sodium
Lauryl Sulfate is a good choice. This material is still
dangerous, but much less lethal than HF. If you would like
us to do this etching, please contact us offlist at:
<>. I strongly recommend that you do not
attempt this yourself.

P.S. Throwing the pieces in your rock tumbler with fine grit
does just as good of a job....and it is not likely to injure

Paul Ahlstedt
P.T. Ahlstedt Mining and Mineral Exploration

Non commercial republication permission granted

Subject: RE: Frosting Black Onyx

<<Hydroflouric acid is the glass froster's alternative to
sand blasting, BUT that is some real deadly stuff.
Sandblasting is much safer and cheaper when done by a local
glass business.>>

Is the etching paste sold in craft stores hydroflouric acid?
If so, what are the safety precautions that should be used
with it? If not, or if it's a milder grade than that used in
the professional processes, is it suitable for frosting black


PS. Thanks to everyone for your advice on lapidary machines.
I did end up getting the Cabmate and am fairly satisfied for
the moment. I'll need to get a slab saw someday, but can make
do for the moment.

"non-commercial republish permission granted"

Subject: RE: Frosting Black Onyx


"Hydroflouric acid" is not only extremely dangerous, it is
spelled incorrectly! Incredible numbers of people are exposed
to this incorrect spelling each year. For the record, the
actual spelling is "hydrofluoric." (Ditto "fluorite" and

Peter Margolin

noncommercial republish permission granted

Subject: RE: Frosting Black Onyx

By the way - please note that the acid which dissolves glass,
quartz, etc is spelt hydroflUOric and not hydroflOUric!!
Likewise flUOrescent!!! I do come all over pedantic at times,
don't I?

You might be interested to know that my wife used HF just
about every day for many years, when she was doing clay
analyses in a brickworks laboratory. She never had any
problems because she was careful with the stuff. I also used
it quite a bit too, in the long ago days when we worked
together in England. We met in a lab in 1939!

At sunny Nelson NZ (in midwinter)

Non commercial publish permission granted.

Subject: RE: Using Water with Dremel or Drill

(Hale's translations of John's NZese are in square brackets

G'day [Hello]:

I noted the thread on the Dremel. I just checked my mains
model (240v AC) Dremel power plug and noted that there are
just the two power contacts, with no earth [ground]. BUT the
case is of plastic, and therefore the earth shouldn't be

BUT! I am a skeptical sort of bloke [chap], and found that
there is electrical continuity between the flex shaft chuck
and the socket that fits into the Dremel. There is also
electrical continuity between the shaft of the Dremel itself
and the metal knob one presses to stop the shaft rotating
when one fits the flexshaft to the Dremel.

Thus there is a potential electrical connection between the
motor shaft and the flexshaft chuck, and of course, the little
knob. Notwithstanding all this, I reckon the little machine
is reasonably safe providing no water gets into the motor
housing and nothing else goes wrong.

However, the device we call an 'earth leak detector' [GFI]
will avoid fatal or even merely unpleasant shocks to the
operator of any electrical machines. I have my entire workshop
wiring set up through one of these devices and I tested mine,
finding that a mere 9 milliamps to earth (I think you call it
'ground' in the USA) - even via the human body - causes the
device to trip instantly and cut off all power. But it must
be remembered that it is NOT a kind of fuse and that a short
circuit will not trip it, unless the short is to earth. There
you go.

Cheers [TaTa]
At sunny Nelson NZ (in midwinter)

Non-commercial publish permission granted.

Subject: RE: Source for Sphere Stands

Reply for sphere stands: napkin holders also make excellent
inexpensive holders for spheres, they come in all colors and
types of material, plastic, sterling silver, wood, decorative
and plain. They will support a 4" or smaller sphere, and do
not detract from the sphere.

non-commercial republish permission granted

Subject: RE: Crystal windows

Hi Sandy:

In reference to you query on the frosted eggs, have seen these
before on the market. The statement "Made in Brazil" holds
true to what's been told of these. Only, Nature did most of
the making. Though I've heard them refered to as "Topaz", and
sold at exorbitant prices, they're actually river tumbled
quartz crystals that have been cut and polished on one end.
I would expect topaz to cleave into oblivion before reaching
the state these are found.



non-commercial republish permission granted

Subject: WTB: Used Double Barrel Rotary Tumbler

I need a good used rotary tumbler in good condition, double
barrel unit preferred. I would love to find a Lortone or
Scott-Murray unit with wing nut seals and iron welded steel
frame, especially Model 8-RB (1/4 hp motor) or even Model
8-RA, a triple barrel unit driven by 1/3 hp motor, both
using 12-lb barrels. Rubber molded barrels running on a
smaller size unit is also acceptable. Price negotiable.
My current tumbler has a good motor but the barrels tend to
wander off the rollers and now have to be taped together.
The seals have started to leak due to the "rubber band"
style closure and the fact that the rubber barrels tend to
stretch with wear and the aging process. I am primarily
looking for a unit with good seals, good motor and
rubber-lined barrels. I like to be able to run two processes
simultaneously, which is the reason I prefer a double unit.

Please send responses to: Rebecca Solon, e-mail address

Hope to hear from anyone interested in selling a tumbler.

Rebecca Solon

"Non-commercial republish permission granted"

Subject: NOTE: Death of Gilbert H. Rowe, Jr.

Hi, Hale - Am writing to ask if you would include a note in
one of your issues to inform anyone who knew Gilbert H. Rowe,
Jr. - "Gil" - who passed away Tuesday, June 16th after a long
bout with cancer.. He was a member of the Lowcountry Gem and
Mineral Society in Charleston, SC and a founding member of the
Charleston Faceting Guild - he was a very devoted "Rock Hound".

I am sure many of your readers will remember him.

Thanks for your consideration -
Sarah McNay

Subject: BIO: Linda Johnson

I finally feel connected!

I have been reading the digest since March and I have gone
back through the archives and found some very valuable
information. Thank you, Hale, for the time and effort you go
to keep lapidary people informed, it has greatly helped me
and given me courage to go on learning new things in the
lapidary field.

My father, Ernie Rossmiller, collected and bought rocks and
faceting material from around the west and Mexico, during
the 1960's and 1970's. He farmed in Montana and wintered in
Tucson. He passed on in 1983. My mother has a permanent
residence in Quartzsite and spends her summer's with us in
Soda Springs, Idaho. We have been to the Pow Wow a couple of
times but without knowing who to talk to it's hard to learn
new things, or get help with problems.

I learned to make cabs and facet and hunt for rocks while in
High School, in Great Falls, Montana. I enjoyed making cabs
and I liked doing irregular stones the best.

Most of the rock collection is here with us in Idaho, and it
is now time to arrive at a price for the different material
we have. Since most of the collection was done over 20 years
ago and the bookkeeping was done in my father's head , I need
some help in figuring out what would be a reasonable price for
things. I also have some crystals from Mexico that are on
wood stands that need to be identified and priced.

Now for the present. My husband is Wendell Johnson, he is a
geologist mining engineer looking for employment. He was mine
superintendent for the per ton largest open pit mine in Idaho.
The company he worked for sold the phosphate property to
another company who brought in their own management people.
We have a daughter that is a junior in college, a son that is
a senior in High School, and a daughter that is a freshman in
High School.

I thought the best way to get the most value out of the stones
is to mount them in jewelry. So I am trying to learn out to
cast and make the mountings look unique. My favorite thing
to do is carve stones but it is going to take a lot of
practice to make them look good.

I have a jewelry store in Soda Springs, that occupies most of
my time now.

Linda & Wendell Johnson
2942 Wood Canyon Rd.
Soda Springs, Id 83276

Subject: BIO: Paul Fanshaw

Thank you for replying to my interest in Lapidary. I have been
fosicking for many years and now have an interest in polishing
and cutting my collection that I have. As I wish to do this
as a hobby and possibly make my own equipment if possible or
purchase some could you please advise.
Thank You

Subject: AD: Irons Lapidary Shop

Greetings Peter and group:

The question once again rises of where to find either
equipment, or supplies. It's hard not to sound like an advert,
sorry. I've located a local (to me at least) supplier who
you might be interested in contacting and getting a catalog
or asking your question. Am constantly amazed at the breadth
of knowledge, and diversity of supplies. Cutting, Carving,
Metal Smithing, Mineral Identification, Faceting, Gemology,,,
sure I forgot a couple.

Irons Lapidary has been dealing in equipment and supplies for
over 30 years. Should you have a need for a catalog of their
inventory, send them an email at <> with
your mailing address, requesting one. Should you have any
question please send it on to them.

And if enough of you ask for the catalog, maybe I can finally
convince them to join the list. The power of the Internet.

Hope they can help.


Subject: WTS: 24" Slabsaw

Hi Hale!
Was requested by my Lapidary Club to post this For Sale item.

The Patuxent Lapidary Guild, located on Ft Meade Maryland,
has a home built slabsaw for sale. It is a 24" saw with a
plywood housing. The housing (approx 30"w x 50"L x 30"H) was
made of plywood and needs to be replaced. Carriage and vise
assembly requires cleaning. Some of the kit parts may need to
be replaced. Motor and next-to-new 24" Raytech Black Blazer
Blade included. Buyer must provide own transportation. First
$300.00 takes it. Contact Tony Wilner at 410-255-4960. Phone
in evening between 6:00 - 9:30 PM EST.

William Collins
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