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

1. LapDigest News for Issue No. 176 - Mon 11/16/98
2. NEW: Crystalite Ringleader Cab Unit Runs HOT!
3. NEW: What's in the Nov'98 Issue of Lap Journal
4. NEW: How to Polish Moonstone
5. NEW: Regarding a Change from SiC to Diamond
6. NEW: Polishing Geodes on Vibratory Lap
7. RE: Slabbing the End Pieces of Rough
8. RE: What Equipment Do I Need to Get Started
9. RE: Dry Vibrating Flat Lap
10. RE: Backing stones
11. HELP: We Need Apatite
12. BIO: Tom Yard


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<MSG1>

Subject: LapDigest News for Issue No. 176 - Mon 11/16/98

I'm back from the mountains, and we did find rubies on top
of Chunky Gal mountain -- but they were very small ones!
Had a great time ... Always get rejuvenated by the
mountains.

I guess quartz - in all its forms - is the most popular
lapidary material we have. Well, today, I spent quite a
bit of time in Roger Pabian's website, at

http://csd.unl.edu/csd/programs/agates/framegem.htm

He has pictures of agates from all over the world - 279 of
them, indexed by location! - and a lexicon and a glossary
to go with his bibliography of information on agates. Go
take a look at it - it is well worth benchmarking!!!

Stay safe, and have a ball!!!

hale
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<MSG2>

Subject: NEW: Crystalite Ringleader Cab Unit Runs HOT!


I picked up a used Crystalite Ringleader Cab Unit, which
appears to be working great. The only problem is that the
motor gets V-E-R-Y HOT. (Can boil water that splashes onto
it.) There is no binding of the shafts at any time, and
when hot or cold, everything spins freely, so I can not
seem to find fault with the bearings.

Is this the way it is supposed to run - hot - or is there
a problem somewhere? Do the bearings or brushes need
attention? Your advice is appreciated....

Fred Gillis, Miami FL
FGillis@jalden.com
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<MSG3>

Subject: NEW: What's in the Nov'98 Issue of Lap Journal


(I was looking for someone to do a quick review of what is
in Rock and Gem, of interest to lapidarys. As I had not
gotten any volunteers, I thought y'all may think that it is
too hard a job. So I did an example using the November
issue of LapJournal to show the kind of review wanted, and
to show how easy it is.)


November Issue of Lapidary Journal?


The November issue has a relatively large amount of
information of interest to the lapidary (for the LJ, that
is!)

First, Fred Ward discusses the nephrite jade found in
northern Canada, called "Polar Jade". (page 22) He says it
is harder and greener than other nephrites. And he describes
the mines, how jade was formed, and how it is mined. Great
background material on this important cutting rough.

Then, Si and Ann Frazier discuss rutilated quartz (page 36)
in a Q&A format: What are the threads inside? What is the
best way to cut it for show? What's a rutile star burst?
What makes some rutilated quartz flash? Is all quartz with
needle-like inclusions rutilated Quartz? Where can you get
good rough? ... And other questions! The answers to these
are important to anyone who works this material. Also has
an extensive bibliography.

In a companion piece, Laerence Stoller (page 71) describes
how to carve rutilated quartz in a step-by-step format.

There are three items in 'Shop Helps' (page 106) which will
be of interest: first, how to test jade to see whether it
will undercut. The second tip is a discussion of how to
work ivory or bone for scrimshaw. Finally, white turquoise
is talked about.

(Hale's note: After writing the above, someone volunteered
to do Lapidary Journal, so we still need someone to do
Rock and Gem!)
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<MSG4>

Subject: NEW: How to Polish Moonstone

<<I only have a Foredom and a medium sized tumbler/polisher.
I am into metal but want to cut and polish my own rough at
some point when $$$ allows.. I would like info on polishing
moonstone.. all the small pamphlets do not address such a
soft, possibly crazed, cracked stone.>>

Polishing moonstone is usually the easiest part of the
process. I like using cerium oxide mixed to a thin slurry
on felt pads spun rather slowly. Do not overheat the stone
(reason for the loose polish mix) as you might induce
cleavage.

Orientation for the best optical effect can be tricky, you
may get a moon", or a cat's eye, or a four rayed star from
some of the asian material, local stuff (NC, VA) has a nice
blue flash. Grind slowly, light pressure, sand as per any
other soft stone.

My 2¢, hope it helps.

Earl
ewenglish@blueridge.net

non-commercial republish permission granted.
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<MSG5>

Subject: NEW: Regarding a Change from SiC to Diamond


The grit sizes that you are using now with silicon carbide
will continue nearly the same as with diamond. The major
difference will be that you will have to use upper stages
of diamond that you didn't have to do with carborundum.

What???

Okay, for instance, when you are using a 600 silicon paper,
only the first minute or so will it cut a true 600. In very
little time, it will break down and cut finer, hence the
old adage of using a worn 600 cloth before going to the
polishing stage for harder material (like 7+).

You are actually burnishing the stone on a worn paper/cloth.
With diamond, it will still cut a 600 scratch until you
knock all of the diamond out of the wheel/resin. It won't
wear away to nothing like silicon carbide.

That means that now you have to go through several higher
stages to remove (progressively) the scratches. 3M and
Crystalite both have their recommended stages to go through.

If you are using expandable drums, you will be buying things
like 3000 grit belts. Crystalite has two types: grinding and
polishing. The grinding starts at 70, 120, 220, 400, 600
'grits' and the polishing 220, 600, 800, 1800, & 3500. You
do not need to follow these series. On hard jaspers, I've
gone from a 70 to a 600 (grind) and then to an 1800. The 600
grind really cuts! For what you are cutting, a 220 & 600
grind and a 600, 1800 & 3500 might be all you ever need. I
have the luxury of several Poly arbors and use several drums
preset, but still change belts. For hard wheels, you may get
by with a 100, 360, and 600. It will all depend on your
setup. With lots of arbors, you have the advantage of
several wheels at your disposal. Changing wheels is not
as fun or simple as some manufacturers would have you
believe. A single drum is fast and easy though.

One thing you will appreciate is how much smoother diamond
will cut, and continue to cut. A further note on diamond:
let it do the cutting. You do not need to use the same
pressure as with carbide wheels. Too much pressure is a
detriment to diamond - it will knock it out of its plating.
Also, always use water. Otherwise, the heat will cause the
diamonds to come loose.

Brewster McShaad
brewster@pacbell.net

P.S. Don't throw away your silicon carbide...you may find
it useful in many applications still.

Non-commercial republishing permission granted
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<MSG6>

Subject: NEW: Polishing Geodes on Vibratory Lap


Speaking of gluing rocks to wood brings up a question I've
had. I have the butt end of a geode I want to polish but I
need to add some weight to it.

I've thought of using "water glass" to glue a piece of wood
to it (to which I would also attach some weight). The
important thing is to use a glue that can be built up
between the wood and the rounded exterior of the geode and
that can be dissolved off the geode afterwards. Has anyone
tried this or have another method?

Thanks,

Dave
drawlins@geocities.com
-----------------------------------------------------------
(Note: Dave I have never tried this, but it would seem
logical to cut a circular hole in a piece of plywood, and
cut it at an angle (with a scrollsaw or jigsaw) to fit
as closely as possible to the geode. This could then be
glued with any soluble cement, and the weights attached to
the top of the plywood. If the hole is the right size so
that the plywood is about half way up the geode, and if the
plywood extends past the edges of the geode, it might also
act as a bumper. Split a hose and fit it onto and around the
rim, secured with a couple of nails.

You should protect the inside of the geode to keep grit and
slosh out, by filling it with something which can also be
removed later when the polishing is through - maybe soap.
I'm sure our vibrating lappers can suggest suitable
materials to fill the geode. hale)
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<MSG7>

Subject: RE: Slabbing the End Pieces of Rough

The trick using silicone to mount rough for slabbing is a
good one.

At our club we use Elmer’s Carpenters glue after the first
cut is made; be liberal and let it set 24hrs. The remaining
thin slab will come off after a week soak in water and some
times the end pieces make nice flat lap material.

You can also mount small pieces for cutting on the trim saw.


Carl
Carl C. DeMuth
<luv2surf@evansville.net>
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<MSG8>


Subject: RE: What Equipment Do I Need to Get Started


Dana:

You are at the same place I was about two years ago. I did
one thing but now I recommend doing something slightly
different. I too am a jeweler/metalsmith who wanted to cut
my own stones. I couldn't afford to spend a lot of $ but I
had to rethink that one. Lapidary equipment does take some
money.

I bought (used) an 8" trim saw, and two Lortone arbors w/ 2
8" wheels each. One of the Lortones had 120 and 220
carborundum green wheels and the other had two 8"
expandable drums.

The 8" trim saw was a good idea. Because I can also slab
small chunks. Friends with 4" & 6" trim saws wish they had
my larger saw.

The arbors where just okay. I have grown less fond of the
carborundum wheels as they occasionally chip my stones,
get outta shape, and can't cut on the harder materials.

I have recently purchased a Hi Tech Diamond 6" All-in-One
flatlap. This little marvel sits by my workbench, is clean
and tidy, and does a great job on shaping cabs. Plus it
was relatively inexpensive, as lapidary equipment goes.
It's downside is that some people don't like the flat lap
way of shaping, I don't mind it, and you must change discs
between steps....a very easy job. Plus I love the way I
can flatten out river rocks and pebbles with this. I can't
do that with an arbor type machine nearly as well. I'm
sure I will still love it dearly in 5 years.

My next purchase will be to get a Genie Pixie. But they are
expensive. So I must work up to that. The nice thing about
them is that there are 6 wheels on this so you can move
back and forth quickly between steps with no changing of
wheels. You can have several cabs going at different stages.

The Lortones will be pushed further to the back of my
studio and probably be sold at some time. Tho' I do like
the expandable drum sanders.

My RECOMMENDATION to you:

Get yourself a larger trim saw (used if you can) so you
can trim and slab small chunks.

Get a Hi Tech Diamond 6" all-in-One-flatlap. This should
cost around $270. Does a great job for less money.

Save your money and think about a Genie Pixie.

With the trim saw and the flatlap you are in business and
can do just about anything you will need for your
metalsmithing.

Now there are lots of details I have left out. Please feel
free to email me if you have any further questions.

Hope this helps. PR

Carla

"non-commercial republish permission granted"
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<MSG9>

Subject: RE: Dry Vibrating Flat Lap

Regarding the dry running of a vibrating flat lap:

Two things happen. 1) it will scare the daylights out of
you. Not a big deal. 2) for what ever reason, things really
start to bounce around as it looses its adhesion caused by
the water.

When things start to bounce, little chips and spalls occur.
Now that is a real problem-you can look at a long, several
pound smokey quartz xtl that I have that will never be the
same from the pounding it took. Don't, I repeat, don't run
your lap dry.

I have happened on pail and trash can lids for a couple of
my flat labs and they have curtailed the time it takes for
a lap to run dry. Greatly. On one lap that I haven't found
a lid that will fit, I built a (albeit a flimsy one) plastic
covering over the lap...a little 'house' for it. It now runs
'wet' with very little administering water on it. It also
keeps grits and sludge from covering everything in the
vicinity. If you can find lids that fit, though, they work
really slick, as it cuts down much of the mess and you will
be checking your rocks long before the pan dries out. A
couple of pieces of duct tape holds the lids in place just
fine should they tend to bounce off.

As to the problem of too much sludge, try cutting down on
the amount of grit that you are using...you can always add
more. I usually add grit several times when I hear the
grinding noise come to a stand-still. As to the pits that
occur, I start off with as fine as a grit as I can get away
with. If you have deep saw marks, you will have to pay the
price and grind forever. It would have to be a fine specimen
for me to grind saw marks out of a rock. I have used a 60-90
only once. Won't do it again. A 100/120 is about as large a
grit that I start with. As it breaks down into smaller grit,
I add a little more until I'm done grinding. If you check
the rock frequently, the grinding doesn't take that much
time.
An old trick is to take an aluminum pencil to it making
marks all across it, put it back in pan for a few minutes
and see if they disappeared. If they did, it is ready to
move to the next stage.

Brewster McShaad
http://home.pacbell.net/brewster
brewster@pacbell.net
non commercial republishing granted
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<MSG10>

Subject: RE: Backing stones


Sorry for being a little late with this. I had e-mailed it
directly to the individual (Sally) who requested the
information in Lapidary Digest issue #171. At the time, I
didn't know how to submit anything to the list. Got an
e-mail from Sally today that praised the idea and made me
blush a little. She asked me to post it, and since I now
know how...here goes. The message to her was as follows...

Not sure if this is the most efficient way, but when I back
cabochons with anything that is that viscous, I push them
face-first into clay with a small device that I made (three
small metal pins welded to a flat plate about 1 1/2" in
diameter. The three pins form a triangle that pushes the
cab evenly, and the plate rests securely on the top of the
clay when the cab is pushed to the proper depth.

Then I just remove the device and pour the semi-liquid on
top. The device ensures that the back of the cab is level
(although slightly sunken). When the liquid hardens, just
pull it out and wash it off. If you are using naturally
shaped stones though, you might not get an even push, and
the liquid may seep around the edge. I would flip the
stones over and make a little clay dam around the back,
then put the stuff into the "mold".

Hope this helps.

Todd
treasure@dfn.com
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<MSG11>

Subject: HELP: We Need Apatite


Hi fellow rock hounds,

The Greensboro (NC) Gem and Mineral Club will hold our
annual Gem and Mineral Show and Sale December 4, 5, 6 at
the Natural Science Center of Greensboro (NC). This is a
new location for our show and allows us to do more
educational programs for kids.

On Saturday, we will be teaching the Geologist Pin to
Webelos scouts. We make hardness kits with the kids. Small
problem: I am out of Hardness 5 material. I know, I can use
a nail for 5.5, but I could use some mineral material of
hardness 5. We have used Apatite before, but only have 23
pieces left. I have 106 boys signed up and 38 on a waiting
list to earn the pin that day.

If you have hardness 5 material that you would be willing
to either donate or sell very inexpensively, please contact
me off list. This is for scouting.

At our Rockfest in August, we did the same program and
expected 25 to 30 boys. We had 89! We are overflowing
with response and out of material.

I can trade you hardness material if you want! I have
plenty of feldspar (6), quartz (7), calcite (3), talc (1).

Thank you.

Mark Case
MarkCase@aol.com
Vice President, Greensboro Gem and Mineral Club
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<MSG12>

Subject: BIO: Tom Yard


Hi! My name is Tom Yard. I live in Oregon. I have been
working with rocks for the last 5-6 years. My specialty is
sphere making. I have constructed my own sphere machines
copied after the popular 3 head design made by Richardson's
Rock Ranch in Madras OR. I have 3 saws, 12", 16" & 24."

I am currently trying the perfect the polishing of large
flat specimens. I have a 24" vibrating flat lap that I am
learning how to become proficient with. My collection is
varied with most material from the West coast here. I am
always looking for material from other locales. I have been
spending my rock cutting time this fall building a shop for
my equipment. My wife feels that she should be able to park
the car in the garage. Priorities, priorities.

Thanks for the Digest. I am eager to learn more about the
lapidary arts from your readers.

Tom
TKYARD@aol.com
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