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 240 - Mon 10/18/1999
2. NEW: Filling Cracks in Opals
3. NEW: Learning Tumbling at Home
4. NEW: What Adhesive to Attach Rock to Wood
5. RE: Notes from Lightning Ridge
6. RE: List of Chatoyant Rocks
7. RE: List of Chatoyant Rocks
8. RE: List of Chatoyant Rocks
9. RE: Need Source for Pulley, Belt and Arbor
10. RE: Need Source for Pulley, Belt and Arbor
11. RE: Flashes of Light when Cutting with SiC
12. RE: Cutting Dop Sticks
13. RE: Cutting Dop Sticks
14. RE: Cutting Dop Sticks
15. RE: Cutting Dopsticks
16. RE: Cutting Dopsticks


Subject: LapDigest News for Issue No 240 - Mon 10/18/1999

Well, we just had another hurricane come up from Florida,
but it swerved at the last minute right out to sea. Thank
God! It's projected track would have taken it right over
the still flooded towns and fields of Eastern NC! We had
only a bit of rain. Thinking we would have a downpour, I
stayed home with nothing to do -- which you can tell by
noting that I commented on almost every message. Cabin
fever = over-commenting.

I did spend one day writing a new set of instructions for
searching the Archives, and after they are reviewed and
corrected, I will publish them here and also put them up on
the Web.

Hope all of you are well -- take good care of yourselves and
be sure to kiss and hug those you love! And HAVE FUN!!!


Subject: NEW: Filling Cracks in Opals

Dear Hale:

A customer just asked me if anyone knows what to use as a
filler for a cracked opal he has. I've tried a number of
things including Opticon with little results. Maybe someone
out there knows. Probably it has already been discussed on
your forum.. let me know if you have some ideas..


Peter Brusaschi
Peter: This has been discussed, but let's do it again. Next
week, I will again take an opal class from Joe DePetrie (who
I studied under a month or so ago), and he has crack filling
in opals down pat. I will try to get him to write something,
or I will take good notes, this time, and write it myself!!

Subject: NEW: Learning Tumbling at Home

Hello everyone:

I am very new to the lapidary arts and trying to teach
myself. I am having very few good results in my tumbling
processes. I live in the Seattle, Washington area (Duvall
to be exact) and am trying to find classes I can attend to
get me started right. I work days so my times are somewhat

Any suggestions?


Subject: NEW: What Adhesive to Attach Rock to Wood

We slab 9" slices to about the center of a rock and bond a
wood 2"x6" to the sliced side to enable slicing the rest of
the rock, presently using sodium silicate as the adhesive.

Any ideas on using an alternative adhesive?

This is a useful tip; after you glue the cut rough to the
2x6 and after you have cut what you want from the rough
piece, just put it on a shelf (with other pieces of rough
glued to wood) and next time you need a slab, it is ready
to cut!

To answer your question, I imagine you also want a glue
joint which can - without too much work - be made to come
"undone"! If so, there is always 'white glue', which also
is water soluble.

If you are planning to keep the wood piece on the rough,
then for any water soluble glue, I suggest you cover the
wood/glue joint with a waterproofing material - possibly
fingernail polish or (?). Otherwise, if you are using water
as lubricant, the water may eventually weaken/destroy the
bond. hale

Subject: RE: Notes from Lightning Ridge

hi, i was in error reporting the accident recently, mario
the buyer was not involved. it was another mario. rumours
fly thick here.

our name of lightning ridge is well justified. the name came
into being over 100 years ago when a shepherd and some
hundreds of sheep were incinerated by a mammoth lightning
bolt; the name stuck. a few nights ago the whole town was
awakened by a crash that sounded like the earth splitting in
two. it was the tv and radio repeater antenna taking a
direct hit.

Dr Ram Pratap, lightning ridge resident for many years was
killed in a light plane accident near brisbane a few days
ago and will be sadly missed by his many friends here and
in the great world outside our little town.

i know i promised mining machinery, but i have to go to
sydney this morning so it will have to wait. we have a 7
hour drive up the western falls of the great dividing
range, and over the top to the coast. some magnificent
scenery on the way. i am looking forward to the cool
climate, as the past few days have hit 35 deg. C.

gotta run,

If you want to see a picture of the Ridge with lightning,
go to While you are there,
you might also look around at the pictures of LR. From that
I read, there are ironstone ridges all around which attract
lightning, much as does a lightning rod!! hale

Subject: RE: List of Chatoyant Rocks

<<Does anyone know of a good list of rocks that exhibit

I don't know of any such list, but if you write one, be
sure to include...

* Man-made fiberoptic stone. I've seen it in 12 different
colors, as low as $4 for 4 cm sphere -- at the last
Denver show, heard about second-hand.

* Chatoyant jade. A new rarity, found in Nevada,
displayed for sale at the Denver show.

Alan Silverstein

Subject: RE: List of Chatoyant Rocks

I searched for such a list and did not find one. So I
suggest we would start one and when it seems complete, put
it in the Archives. Let's make this a list project!!

But first, let's define a few words: Stones which show an
optical effect in visible light are called PHENOMENAL
stones, and there are several phenomena which can cause a
stone to be called Phenomenal, and they are:

Adularescence - is a strong pearly to blue glow as seen in
feldspar moonstones (orthoclase, albite or
Asterisn - is a star of 4, 6 or more rays shown in stones
with oriented inclusions.
Aventurescence - is a sparkle effect from metallic or glassy
reflections from spangles of mica or other minerals.
Chatoyancy - is a gleaming effect including overall shimmer
or distinct cat's eyes.
Iridescence - Play of colors or rainbow colors, sometimes
metallic looking.
Labradorescence - is a broad flash (of various colors)
across the surface of the stone.
Schiller - is a directional sheen or shimmer.
Opalescence - A milky appearance similar to a moving cloud.

Not all books/sources agree on these definitions; there is
possibly a difference in the way mineralogists define them
and the way lapidarys define them. So for our purposes, I
will stick to the lapidary usage and use the definitions as
given by June Culp Zeitner in GEM AND LAPIDARY MATERIALS,
page 236.

When 'Lenny from Seattle' posed the question: "Does anyone
know of a good list of rocks that exhibit chatoyancy?", I
didn't know whether he meant only chatoyancy or did he mean
any of the phenomena listed above. In making this list, I
have adopted the wider question about rocks with ANY of the
optical phenomena. Thus this is really a list of Phenominal
Stones! Zeitner says there are about 50 stones which show
these effects, and even so, they "are usually limited to a
minor proportion of the stones of each species." I am also
including stones which are usually only faceted.

My list, so far, unordered and incomplete, is shown below.
All members of the list are invited to add the names of
stones with special optical effects to this list -- but
please cite source of info and type of phenomena, even if
it is anectdotal.


Chatoyant Malachite: (
Fiber Optic:
Labradorite - feldspar
Spectralite - "
Orthoclase - "
Albite - "
Oligoclase - "
White Selenite
Star Rose Quartz
Blue TigerEye
Red TigerEye
Cat's Eye Opal (from South America)
Rainbow Hematite
Iridescent Hematite

Please feel free to add more to this list, but cite sources
and URLs of pictures, if you can.

Hope this helps....


Subject: RE: List of Chatoyant Rocks

Hi Lenny & Hale:

I bought some marramumba (the way they spelled it - however
I have seen other similar spellings) at the Tucson show in
February. It is really different, and much more striking
than regular tiger eye. However they told me it was a
distant relative of same. It is rather expensive I think,
but the cabs I have (30x40) are just beautiful. Am having
some of it wirewrapped.

Here is the address I have on my sales receipt:
Tel. # 818-541-6931

Might give them a call, or maybe someone else has an idea.

Willa Kleymann
I searched for this name on the 'Net, and could not find a
single reference to it!! Anybody know of any reference to
it? If you live in Glendale - so that it is a local call,
please call them and ask about this rock: locality, minerals
in rock, colors, other names, and so on. Thanks hale

Subject: RE: Need Source for Pulley, Belt and Arbor

<<Anyone know of a good catalog source, on-line or snail
mail, for v-belt pulleys, belts, shafts and so on?>>

Hi John: Try this site.

Criss Morgan
Sorry, Criss, none of those catalogs had any of the things
he was searching for -- but I sure did get a lot of ideas
for Christmas presents!!! I also searched a usenet archive
and found a good catalog for parts for building lapidary
equipment: And they have their
catalog on a free CD-ROM. hale

Subject: RE: Need Source for Pulley, Belt and Arbor

Don't you get any of those catalogs in the mail that have
that kind of stuff in them? Like Northern Merchandise, etc.
You didn't say where you are from but, any Eagle Hdwe, Home
Depot and Home Base should have them.

Don't you have a machine shop supplier? Sears? Don't be
afraid to ask!!!!!!!

James Bergen

Subject: RE: Flashes of Light when Cutting with SiC

<<When I grind quartz crystals on my silicon carbide wheel
I can see flashes of light and this makes sense being that
quartz is piezo electric and compression makes light,

Flexing piezo electric crystals makes electrical potential,
but usually not light flashes.

<< Well I'm making a cab out of a huge apache tear and it is
really doing a lot of flashes of light and now I wonder
where this is coming from? Is the carbide wheel causing the
light or does obsidian have piezo qualities?>>

I think what you're seeing is minute white-hot pieces of the
material you're cutting.

I agree with you. Al. Sometimes I see students pushing a
slab into a saw blade till there is a steady continuous
point of light at the point of contact; with diamonds, I
think I know that this is bad and the heat will soften and
wipe the metal over the diamonds, dulling the blade. I have
never cut with SiC, so don't have experience, but I would
think that he is pushing too hard. hale

Subject: RE: Cutting Dop Sticks

(Dave noted that poorly cut dopsticks were a hindrance to
cutting symmetrical cabs; here's a reply to that statement,
I think - hale)

Hello Dave,

If you insist on denying yourself access to the wonderful
world of freeform art cabochon cutting, and cutting for
your jewellery rather than jewelling gemstones like most
jewellers do (this list obviously excepted), then I may be
able to help but I cheat, I use my faceting machine. How
precise do you need?

With wheels however, if you are using dop sticks, an
aluminum template will leave white marks on your preform
showing where the stone is big. A taper on the preform
allows you to get the outline shape correct before you reach
exact dimensions. Without a stick you need to use the tool
support and slide/push the preform into the wheel up to the
pre marked outline. A template is used to finish the precise

A preforming machine is the ultimate luxury as all the
preforms are cut precisely what you set the machine for. I
have had several, the hand cranked thingy, a single stone
electric motor powered clamp on device, a used spectacle
lens grinding machine and a few full size professional
multiple stone production machines. I have seen but not used
a few homebuilt units of varying efficiency. They all
produce a dimensionally exact preform. Taking the precise
preform to an accurately finished cab is usually quite

I have no experience with SiC wheels, the idea of having a
tool that is constantly changing shape, creating unnecessary
filth and proven lethal in operation does not appeal to me.
I have yet to stand in front of one nor will I stay in a
room if one gets turned on. The first things to go when I
bought my rock shop was the SiC wheels, all of them. I
didn't want any on the premises and certainly would not sell
them to any of my hobbyist customers. Cheap? I wonder how
many dozens of grinding wheels would have worn out in the
last 25 years trying to keep up with my 'Ripple disk', which
is still about as flat as it was when it was new and still
eats sapphire, or SiC come to that in very short order, oh
and another thing, it has yet to cut, abrade or injure my
fingers. I bet this opinion isn't popular :-)

The other day Patrick needed some opal cabs to fill an order
and was short by a few rounds, 6 to 10 mm. sizes. I slabbed
and trimmed some suitable rough and dopped the squarish
chunks. I chucked up a piece in my quill, locked the stop
and started spinning the handpiece. Patrick then asked if I
could have them all cut before his appointment...."No!" I
handed him the block with the dopped opal chunks and pointed
at the diamond wheels, "How good are you at cutting rounds
free hand?". The stones all got cut and we were about even
as far as production speed but I was surprised to notice
when gauging the finished stones that his 'freehand' stones
were the match and some better in accuracy than mine. All
those years living in a hole in Coober Pedy, bellying up to
a cutting rig with his fresh nobbies paid off I guess. I
think everyone will agree that the more you cut the easier
and more precise your cutting gets and the more fun you have
doing it.

Have fun..

Art Jewellers On-Line Gallery and promotional collective for
jewellery artisans. To subscribe to our newsletter please

Subject: RE: Cutting Dop Sticks

buy a cheap miter box. . . .you can get them at most garage
sales for a couple bucks or make one out of scrap 1 x 4 t
hen get a small back saw or whatever and you're in business.


Subject: RE: Cutting Dop Sticks

Hi, I found that if you have an old variable speed drill
you can put the dop stick into the drill and turn it
against a piece of fine tooth hack saw blade secured in a
vise. The turns will be precise and cutting a circumference
makes a smooth flat surface.

This site is a wonderful help to the beginner in the
lapidary trade and some of my ideas come from my wife’s craft

Good luck

Subject: RE: Cutting Dopsticks

<<Any ideas on how to square the end of both a small and a
large dopstick?>>

One of the cheapest ways to cut wood dop sticks is to go to
the hardware store and purchase a tubing cutter. If you
purchase one up to 3/4", it may not cut all the way through
but it will cut deep enough to break it off and then trim
with a knife. The line around the dop will be square.

Jerry Miller

Subject: RE: Cutting Dopsticks

Well, I figured out an easy way to square cut dopsticks
from dowels. Any hardware store sells these small aluminum
mitering frames made by Xacto I think, and it comes with an
Xacto saw blade. It has a 90 degree slot in it and even
though the clamp won't hold dowels you can pretty much hold
the dowel against the side with your hands tight enough to
do the sawing. You get a nice flat square cut which is what
I was looking for.....

Crystalguy Jewelry, Art Jewelry for the Mystic Soul
Paddle Jewelry for River Addicts
Dave: It is nice to have a square-cut dopstick, but more
importantly, you should be sure that the preform or slab is
at right angles to the dopstick when the wax cools. Even
with a square ended dopstick, it is possible when attaching
with wax to end up with the back of the preform NOT at right
angles to the dopstick. It is best to have a square ended
dopstick, but the critical step is to ATTACH the stick
perpendicular to the back of the preform or slab. And you
can do this even if the dopstick isn't squarely cut!! hale
To unsubscribe from the Lapidary Digest, send a message to, with the word UNSUBSCRIBE DIGEST as
the subject of the message. Other commands you may use are:
SUBSCRIBE DIGEST to join, HELP to receive a page of help
instructions on the use of the list, and DIR to receive a
list of names of all files in the Archives.

The command <GET filename> may be used on the subject line
(without brackets, of course) to obtain a copy of the file
named "filename". Type filename exactly as it appears in the
directory, including the extension txt. Do not cut-and-paste
filenames into the subject line.