Edited and Published by Hale Sweeny
Web Site: http://www.lapidarydigest.com
Associate Editors: Geo. Butts, JR Shroeder, Steve Henegar,
Margaret Malm, and Sam Todaro
This list digest contains the following message subjects:
1. LapDigest News for Issue No 270 - Tue 4/4/2000
2. NEW: Colors on Raytech Diamond Disks
3. NEW: Adhesive for Doublets and Triplets
4. NEW: Polishing Setup
5. NEW: Difference - Dendritic and Moss Agates
6. RE: Cutting Something Concave
7. RE: Cutting Something Concave
8. RE: Tin Oxide Buffing Compound
9. RE: Inexpensive Cabbing Machine
10. RE: Spencer Opal
11. RE: Spencer Opal
12. RE: Expanding Drum Problem
13. RE: Polishing Jade in Tumbling
14. RE: Polishing Jade in Tumbling
15. RE: Polishing Jade in Tumbling
16. BIO: Jack King
17. BIO: Amy O'Connell
18. BIO: Warren Kruger
19. FS: Lortone 2 Wheel Arbor
20. SHOW: Amityville NY
21. SHOW: Open House in Greensboro, NC
Subject: LapDigest News for Issue No 270 -
IMPORTANT INSTRUCTIONS: Sign your name to submissions, and
restrict your messages to one topic per message. PLEASE!!
If you do multiple topics in a letter, I must take it apart
and rewrite it as multiple letters, and this just takes a
lot of time! So PLEASE ...
There are now more than 3000 threads in the Archives; hope
you will search them and try our new keyword search engine
to find answers to your questions. You'll like it! Try it!
There is an Encyclopaedia of Rocks and Minerals on the web,
by Probert; it is divided into three parts:
Names A thru E: http://www.spaceports.com/~mprobert/H1.HTM
Names F thru N: http://www.spaceports.com/~mprobert/H2.HTM
Names O thru Z: http://www.spaceports.com/~mprobert/H3.HTM
Very handy; very convenient. Try it. You'll like this, too!
Amy O'Connell (see BIO below) likes to cut cabs from rarer
cabbing rough stock. If you browse her site at
http://lapidaryart.com/rocks.html, and look in the Rock
Shop, you will see lapidary materials you may never have
seen before. It is worth it (and she would like to have the
counter go higher!!!(smile)
You guys take care, hug the ones you love, and above all,
ps: To new female subscribers, when I say 'you guys', I
mean ALL our members ... As used here, 'guys' is NOT gender
specific!! So please don't write!! (smile) hale
Subject: NEW: Colors on Raytech Diamond Disks
Hello Hale and list members:
I need HELP! I have 4 RayTech "true circle diamond discs"
which I was about to mount on Flexo-disks, but my g'children
got into them, and mixed them up before I had a chance to.
What I need is an e-mail address for Raytech (which I cannot
find), an 800 number for their customer service department,
or some info from knowledgeable people on this list.
The boxes say that I have a 280, 600, 1200 and a diamond
polish disc. The colors are: dark brown, blue, red and gray.
Can anyone positively match the colors with the grits?
Your help will be GREATLY appreciated.
Subject: NEW: Adhesive for Doublets and Triplets
I also normally use epoxy 330 because of its clear drying.
But it's a little thick when you mix it, which means that
bubbles are a constant worry. Someone, either on this list
or on another one, recently recommended an adhesive by the
name of Araldite because it is very thin and runny. I
believe it's also a 2-part epoxy.
Does anyone on the Digest have any experiences with
Araldite, and any idea where I can get this stuff? Or are
there any other recommended doublet/triplet adhesives? What
do the professional opal cutters in Australia and elsewhere
use? How about Canada Balsam? Was that not at one time the
adhesive of choice? What factors speak for and against
Cheers & thanks
Hans: A quick search of the 'Net gave the following info. I
know it is not enough and hope someone on the list has used
it and will chime in.
ARALDITE RAPID - a Quick setting 2 part epoxy resin. Bonds:
ceramics, wood, chipboard, glass, metal & most hard plastics.
Solvent free. Water resistant. Good chemical Resistance.
Sandable. Can be painted. Strong & long lasting. Made by
Ceba-Geigy. Call 800-875-1363 for location of distributors,
and technical questions.
There is another service everyone should know about: You
can refer any technical questions about epoxy to the GluGuy
at email@example.com. I asked them if I could decrease
viscosity by adding a solvent. He said it depended on the
epoxy, and the solvent, and to ask the maker of the epoxy.
Subject: NEW: Polishing Setup
My favorite polishing set up was an old exercise machine I
got for very few dollars at the GoodWill shop. Remove the
Massaging belts and the 2 cam hubs, measure the shaft
diameter and buy 2 sanding disks from Sears or other source.
Glue on the soft leather disks to the aluminum sanding disks
AND THE RESULT IS A VERY LOW COST VARIABLE SPEED POLISHER .
THE PART YOU WERE SUPPOSED TO STAND ON MAKES A GOOD STAND
FOR IT if you reverse it and point the slope away from you.
With 1x6" wheels and a home made splash guard (2 old
brownie pans and some tubing) for draining.
Subject: NEW: Difference - Dendritic and Moss Agates
Hi everyone -
Here's hoping someone can offer me a clear cut answer on
defining and telling the difference between an agate
containing dendrites and one called Moss. I have a bunch of
tumbled agate with well defined green or reddish brown
"veins" like blood vessels. They go through the whole stone
and I need to know if that is considered a Moss agate or
All the pictures I've viewed explain tree like or branch
like forms as being dendrites.. I have single veined ones
crossing the stone, then I also have ones that are so veined
that they almost fill the whole stone with that design but
when you put it to the light, you can see through the places
that are not veined.
Sure could use some help here. I don't want to misname them
because they have different therapeutic values and spiritual
attributions when used for crystal healing sessions.
Thanks to all who respond.
Subject: RE: Cutting Something Concave
Can you get a watch xtal that's larger and already concave
inside? If so, just cut it down to fit. For a quality job,
try to get a sapphire xtal - more scratch resistant.
1 Lucky Texan
custom faceted gems
Subject: RE: Cutting Something Concave
I can offer you two alternatives. Both come from the watch
crystal being a lens that must display the watch face
Take the old watch crystal to an optician, have them
measure it as a lens, and feed it into their lens grinding
machine. A few hours later out pops a replacement. ;~}
But if you would rather do it yourself, you can treat it as
a lens (or telescope mirror blank) and use the hand
techniques amateur astronomers have used for decades to make
their own telescopes and optical devices (and quartz is
often preferred over glass, but they are worked the same
way). Go to your library and find Scientific American's
"Amateur Telescope Making" (Book One, Book Two, Book Three),
Albert Ingalls, editor, or "Making Your Own Telescope" by
Allyn J. Thompson from Sky Publishing (but its not as
comprehensive). You may find other good books, but both of
these are practical, step by step, how to books. Have fun
pushing glass. ;~}
Please visit our family web pages at http://Tomaszewski.net
My suggestion (eyeglass lens cut down) and Carl's (big watch
crystal cut down) and Kreigh's first suggestion will all
solve Tom Wilke's problem, but none of them answers his
question: How do you cut and polish a concave 'hollow' in
a piece of lapidary rough? Kreigh's second suggestion (like
grinding telescope lens) does offer a solution, elegant but
slow and tedious. Can anyone suggest a solution using
ordinary cabbing equipment? hale
Subject: RE: Tin Oxide Buffing Compound
<<I would like to know if anyone has a recipe for making a
buffing compound that is similar to the bar style used with
a standard buffing wheel on a basic bench grinder. I want
to make a tin oxide bar and don't know what works best as a
binder to hold the tin oxide in a solid form (most likely a
I experimented with this question a few years ago. I used
paraffin for the carrier. It works very well. Melt a small
amount of paraffin in a clean vessel. (I used the brass cup
from my Rock Rascal dop pot. Minus the dop wax of course) A
small glass or jar in the microwave should do the trick.
Once the wax is melted stir in the polishing compound, tin
oxide in this case, as much as the wax will take. Then pour
the result into an ice cube tray or any suitable plastic
mold. Put the filled mold in the freezer for a bit. The wax
will un-mold better if its good and hard. Use it as you
would any other buffing compound on muslin or felt buffs.
By the way, this is a very good trick for polishing
turquoise, malachite, and other soft stones.
NOTE: This trick will work with a variety of polishing
powders, try some others. Ive been thinking of making up
some 600 grit silicon carbide as a fine sanding compound
for use in opal carving. If any one beats me to it, please
post your results on the list.
Hope this helps
Subject: RE: Inexpensive Cabbing Machine
I figured I would share the building of my first machine,
Unfortunately it has been so long ago, some of the detail
and prices are a little fuzzy.
1) I found an old cabinet about 2' deep by 3'wide by 3 to
3-1/2 foot high set out for trash pickup- had nothing
inside, just an old very sturdy shell. price- $0.00
2) Also found an old Bar-B-Que out for trash; the cast
Aluminum kind (thick wall-old) with the gas burner in the
bottom (char broil etc).$ 0.00
3) Went to a junkyard and picked up a motor-didn't have to
pull it-it was on a shelf already so I don't know what it
came out of but it had a pulley already on the end. I think
4) Went to a nautical surplus store (junkyard) and picked
up a Two foot long by One inch wide (steel)? rod which
already had watertight mounting bushings on it. I went to
this store for the bushings- (watertight = boats) and just
lucked out on the rod. They also had, for a price, a guy
that would thread the end of the rod (tap & die), so after
I found out the specs on a faceplate, I had him turn a 3/4
thread on the end. I had him go in about 6 inches with the
thread--(for reason # H below). I think around $20.00 for
the rod, another $15 for the thread.
5) Went back to the first junkyard and found a pulley for
the end of the rod, and found some 2" X 8" H. x 6" W. angle
"U" brackets; actually, they are "U" shape, but the
are at right angles so they are a "square "U" -- these
to invert and mount the bushings to. About $8.00
6) Hardware store- misc. large washers, steel pipe large
enough to slip over rod, nuts & bolts, plastic tubing, etc.
7) Automotive store- belt for pulley. around $5.00
8) Bought a 100 and 220 SiC grinding wheel-don't remember
what I paid for the first ones, but I just got some new
ones from Kingsley North and paid around $60.-$65.00 for
both. Also got foam pads, feather Adhesive, assorted disks
400,600 felt pads, etc., around $80.00 for all of it.
A) Went home and unbolted stand from bar-b-que, then bolted
a piece of metal over the large hole in the bottom of the
bar-b-que, where the burner went thru.
B) Drilled a hole in the lower back large enough for the
tubing (drain tube) and put a compression fitting on it
(I had the fitting)
C) Hacksawed the end of bar-b-que for the Face plate, and
the other end for the pulley (Went down about 4 in), Drilled
out and bolted the inverted "U"s along the bottom to mount
the bushings to.
D) Cut out a hole in the top of the cabinet (for the belt of
the pulley) and mounted a shelf inside the cabinet to mount
the motor to.
E) Mounted the motor inside, and the Bar-b-que on top of the
F) Drilled a little indent on the end of the rod for the
set-screw of the pulley to sit in and mounted it.
G) Took the ring from a weight set-its the metal "O" ring
that has a bolt in the side of it-when used for weights,
you put a ring on each side of the actual weight, and
tighten them down to keep the weight from spinning. I put
this on facing in-after the pulley, but before the first
grinding wheel. Had old weight set-no cost.
H) Put on spacers, then a large washer on each side of the
grinding wheels, using the spacers to put the wheels where
I wanted them. Also feeding the bushings on to the rod to
match where I mounted the "U" brackets. When I had them
where I wanted them I put another spacer then washer (all
the spacers are a couple inches long) at the end, and put
a large nut on. I could tighten this down and compress all
the spacers and grinding wheels against each other, with
the weight set lock down at the other end. This made it so
as the rod turned, so did everything else.
I) Bolted down the bushings, ran the belt down thru the
slot, hooked up the belt, spun on the faceplate, foam pad,
or felt -whatever you needed at the time. I went with the
feather adhesive so I could use the plate as a course,
medium, or fine grind. Or switch it to polishing- one piece
J) Built a 3 sided box to place over top of unit. Drilled
out holes over grinding wheels and ran tubing with hose
clamps from a 5 gal. bucket that has holes for the other
end of the tubing. I put the bucket on a higher shelf, fill
with water, and run the water over the wheel I am using at
the time. Leftovers-no cost.
Summing up the costs, we find the approximate total cost
Hale, I tried to remember the best I could, if something
is a little fuzzy, just ask and I will do my best to fill
in the gaps. I used this for years, sold it, and as far as
I know, it's still in use.
Durnings Rings & Things
Subject: RE: Spencer Opal
I wrote the "Kitchen Table Triplet" mentioned in the last
issue of the Lapidary Digest (as seen in the "Eclectic
Lapidary" - go to http:www.bovagems.com and then go into
the "archives".) It describes my own method of making
triplets. Let me just correct one statement in that: I don't
use silicon carbide PAPER in lapping down the elements, but
rather silicon carbide grit, in water, on a sheet of plate
glass as substrate. I lap down to about 220 grit, that's
all. Leaving the stone, the base and the cap a little rough
I feel (without having any scientific proof) gives the epoxy
a better gripping surface and makes for a better bond. The
epoxy makes the roughness invisible.
One thing worth pointing out is that the number of
variations on the basic theme that have been described here
in the Lapidary Digest, all of which appear to lead to
successful doublets and triplets, indicates that the process
is actually rather forgiving. Probably the worst wrong thing
you can do is get oil or bubbles in the epoxy; oil being
fatal for the bond, bubbles for the appearance.
Cheers & thanks
Subject: RE: Spencer Opal
Hi Jed, Noel, and all,
Great piece on Spencer opal triplets Noel! Thank you. I
have a couple of points worth mentioning. In as much as Jed
is on a tight budget, here is a very cheap suggestion for
flat lapping. Heck I use it even when money is not tight,
because it works so well. Diamond laps are pricey, even
after one lays out the money for a machine.
Jed, your iron lap will work great for rough grinding but
will not produce a reliably "flat" surface. Regular use
grinds channels in the lap surface. Iron laps are never
"flat" enough unless you have the laps turned at a machine
shop on a regular basis.
I suggest using a glass plate and loose grit (silicon
carbide of course). A local glazier will usually be happy
to cut a few eight-inch squares from his scrap. I like to
use 3/16 or ¼" thick glass. 1/8" should work just fine
It is important to bevel the sharp edges and corners so you
dont cut yourself. Glaziers are usually quite happy to do
it for you (for a small additional charge, of course) or
you can sand the edges with coarse emery cloth.
I like to use 320 mesh silicon carbide for rough grinding
and 600 mesh for a finer finish. I keep a separate plate for
each grit as courser grits create a rougher grinding surface
on the glass. A finer finish also helps eliminate light
scattering between the opal surface and the bottom of the
cap. Too much light scattering can produce a slight
blurring of the opal. However the epoxy will not adhere as
well to a polished surface. 600 grit is a good compromise.
It is important to utilize the entire surface of each glass
plate to prevent the grinding surface from becoming concave
with use. Once that happens it is impossible to grind a
truly flat surface. Oh well, flip the glass over and use
the other side for a while. One should be able to pick up
glass plates and silicon carbide grit for well under $20.
I have worked with a few Spencer opals and my experience is
not equal to others, who haunt this list. I have a couple
of tips, though, that originate from my work experience as
a petrographic technician (I have produced around 25,000 to
30,000 thin sections to date). It is critical to keep two
things in mind when making opal triplets:
1) Keep all mounting surfaces parallel to the fire layer,
2) Grind all surfaces flat. By flat I mean flat to the
point of ridiculous. The strength of the bond between the
opal and its backing and cap depends, in part, on the
precision of their fit. How well you capture the fire layer
depends on how precisely your ground surfaces match to the
I like glass, it's cheap, flat, and no guilt tossing it
when I've used it up.
Good luck Jed, I hope this helps.
Subject: RE: Expanding Drum Problem
The problem seems to be with the 8 inch drums. If you can
scare up a 1997 Lortone catalogue, they explain things
The Scott-Murray expandable drums made of rubber with the
expanding slots take 25-7/32" long belts either 2 inches or
3 inches wide depending on the width of the drum.
The Exact-span drums - with the foam rubber and the two
pieces of aluminum that must be taken apart to change the
belt - use 25-1/8" long belts. To my mind these are an
absolute pain to use!
The expandable drums are more than twice the price but much
more convenient - providing you buy the 25-7/32" long belts
rather than the 25-1/8" ones! I suspect that people who are
having trouble are buying the wrong size of belt and that
3/32nd of an inch makes a big difference! The size should
be clearly marked on the box the belts come in and a good
lapidary store should stock both kinds - it is up to the
user to know which one they need - ordering a belt for an
8 x 3 or 8 x 2 inch wheel isn't enough! If you are lucky
the person on the order desk will inquire about the
details of your sanding drum.
Karen (who only has 6 inch expandable drums on her little
Subject: RE: Polishing Jade in Tumbling
I barrel polish about 10 kg of Jade a week , mainly shaped
pendants and carvings. I just use the 100 grit to start,
then 400 then 600 then 800.
The final polish I load up my tumblers to about 70% add to
fill the tumbler with a soap flake ( LUX )we get in NZ ,
then water to cover and put in about a small teaspoon of tin
oxide. Then tumble watching to make sure I stop it before it
The final polish is in a vibrator ( a shell case polisher)
loaded with walnut shell with Turtle Wax car polish in it.
They come out nearly as good as a hand polish
Subject: RE: Polishing Jade in Tumbling
I've had great success using a compound from Diamond
Pacific called "VibraDry". I use 2500 grit for a day
followed by 14000 grit for a day. It's dry, it's diamond in
a carrier, it's wonderful, especially since there is no
clean up afterward. I use the normal wet process through
600 grit then switch to the dry compound in a separate
The Jade comes out looking great! ;~)>
Wes Lingerfelt, 1999/2000 Treasurer
Orcutt Mineral Society
Subject: RE: Polishing Jade in Tumbling
If your jade after tumbling comes out dull , it is probably
nephrite, which requires heat to get a good polish. If you
can find jadite or distinguish between them, you can get a
pretty good polish on jadite by tumbling.
Enjoy your hobby.
HOBO of HOBOMATE
Subject: BIO: Jack King
Hello, my name is Jack King.
I live on Lake Norman, north of Charlotte, NC. I own Camera
World in Charlotte for my day job and a passion other than
photography are my rocks. I started about 1954 while growing
up in Graham, NC (not far from you, Hale). I had a Dad who
helped me explore and expand my hobby by taking me all over
the state looking for rocks, minerals and gemstones. My
memories of the Spruce Pine area, for example, were the days
before fears of lawsuits, when mine owners let me crawl on
the spoils at the Ray mine and the miners would leave me
Aquamarine crystals on a hidden stump for my next trip back.
So, after 36 years in the camera business, and with a
grandson, whose interest was caught by some of my rocks, I
have increased my level of interest over the past five years.
I have purchased a big 'ol Highland Park saw, a used Genie,
a used 8" Lortone arbor from an aging Rockhound in Ohio and
a Covington 8" flat lap for which I just received some new
Lapcraft Islander no-hole laps. I'm sorry being so wordy
getting to this, but I tried the flat lap out this afternoon
attempting to grind some flat faces on some rutilated quartz.
First of all, I don't know how much pressure to bear, and
secondly, at least 3 times the lap unscrewed and flew off.
Am I running too fast RPM's ? Am I applying too much
Pressure? This 100 Diamond disk from Lapcraft wasn't cheap
and I hope that I haven't screwed up HELP!
Again don't know the forum format yet , but I sure would
appreciate some feedback either here or call me during the
day at (800-868-3686).
Subject: BIO: Amy O'Connell
I've been reading the Journal for some time now so I thought
I better get around to introducing myself...I am a jewelry
designer, lapidary, and photographer in the San Francisco Bay
Area. I've been making jewelry for 6 years and just started
doing my own stone cutting last year. Between the 6 years of
jewelry fabrication and 4 years as a dental lab tech,
lapidary came naturally and I'm completely hooked. I go to
every stone show and rock shop I can find. I'm always
looking for new and unusual materials.
I also spend way too much time at the computer and working
on my website. It's been growing a lot lately. In January I
launched my on-line rock shop where I sell a lot of my
unusual cabs: http://LapidaryArt.com
Along with the jewelry, the rocks, and the website I also
do small scale photography for other jewelers. I'm 28 and
feel very privileged to run my own business and be part of
groups like this list. I moved to California 2 years ago
from Iowa and have met many fantastic artists and rock
enthusiasts in person and on-line. I'm so glad there are so
many people willing to share their knowlege.. I just want to
keep listening and learning.
Amy O'Connell Jewelry
Subject: BIO: Warren Kruger
My name is Warren Kruger. At this time I have two cabbing
machines (both by Graves) and enjoy making cabs for belt
buckles. I want to learn more. I have been at it for one
to two years.
Subject: FS: Lortone 2 Wheel Arbor
In the last issue, you mentioned a request for an
"Inexpensive Cabbing Machine". There was a similar request
a couple of months ago from a gentleman to whom I replied
'off list'. Shortly thereafter I had a computer 'meltdown'
and lost my 'past life'.
I had intended to suggest to him that I have a used Lortone
6 inch 2 wheel arbor, with 100 and 220 SiC wheels with
years of life left, and plumbing in place. It is much like
todays 'Beaver' arbors, if not the same. It has been in the
garage for some years, and has some rust on the shaft,
which can be easily removed with a strip of sanding cloth
on a rotating shaft.
If that gentleman reads this, my offer was going to be
$75 plus shipping, or $100 and I pay shipping, whichever is
Subject: SHOW: Amityville NY
Island Rockhounds Inc. Invite one and all to our
28th Annual FESTIVAL OF GEMS & MINERALS
American Legion Amityville Post No. 1015
79 Park Ave Amityville NY
Saturday, May 6, 2000:10 - 6 ;Sunday, May 7, 2000:10 - 5
Questions can be directed to John Andersen (516-781-8410)
Subject: SHOW: Open House in Greensboro, NC
The Rock and Mineral Society of Greensboro invites all
rockhounds to our first open house event: Sunday, April 9,
1 to 4 PM at the Natural Science Center, Greensboro, NC.
A field trip in a bucket: (Rock swap). No selling will be
allowed, but you can take names and numbers and conduct
transactions later, off the premises.
We will have demonstrators for faceting, cabbing and wire
trees and I will be demonstrating wire art jewelry.
For more information, please contact me off list and y'all
Mark H. Case, Sr.
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