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1. LapDigest News for Issue No. 194 - Fri 1/15/99
2. NEW: Flat Lapping Around a Cavity
3. RE: Where Do Opalized Clams Come From?
4. NEW: MK tile saw
5. RE: Surface Tension
6. RE: Surface Tension
7. Re: Orienting Montana Agate for Cutting
8. Re: Orienting Montana Agate for Cutting
9. Re: Orienting Montana Agate for Cutting
10. RE: Need Info on Diamond Polishing Belts
11. Re: BIO of Margaret
12. RE: Lapidary Journal December Review
13. RE: Which Oil to Use in a Slab Saw?
14. Re: Questions about an Opalized Clam
15. BIO: Kimberly Freedman
Subject: LapDigest News for Issue No. 194 - Fri 1/15/99
Well, you really went wild this week, didn't you? The
Digest received 34 messages - far too many for one issue,
and a lot to edit! So I have broken the next issue into two
issues. If you don't see what you sent in, just wait, it
will be along in a day or two!
Take care of yourselves, and good cutting!!!
Subject: NEW: Flat Lapping Around a Cavity
I have just cut a very attractive piece of flint for
bookends. I unexpectedly found a lovely pocket of quartz
crystals right in the middle. Now I have the problem of
polishing the two surfaces of the pocket which I split and
not get any slurry into the crystal pocket.
Someone here (in South Bend) suggested coating the pocket
with shellac, grind and polish, and then soak in alcohol
to remove the shellac. When I thought it over, it seemed
to me that I would be soaking off a very dingy gray mixture
of alcohol, shellac and slurry, which would then get on the
I've thought that something like expanding foam insulation
might thoroughly fill the cavity and keep all slurry out.
However, I'm stumped on how to get it out completely.
Don't know what will dissolve it.
Has anyone ever tried the shellac approach? Does anyone
have other ideas?
Subject: RE: Where Do Opalized Clams Come From?
Opal Clams predominately come from an area in Coober Pedy
Opal fields. Some Areas Produce larger amounts of Clams and
others very few. I have a nice collection from large 4inch
down to a tiny 5mm clam.
Not only Clams are available, Mussels and a Wide variety of
other Shells and fossils come from this vast Opalised Area.
Unfortunately most of the mussels are not opalised but there
are lovely specimens of mussel clusters currently available
from many Coober Pedy Miners.
The Majority of Clam Shells are Opalised, however only a
small percentage contain Gem opal. Those shells that do
contain top Gem opal were in the past sold and cut for
Jewelry use with no regard to the fossil value. Only
recently has the Fossil value of a clam become a saleable
feature. But then not many will pay the high price asked
for a top gem opal clam as a specimen when compared to the
money one could obtain from cutting the clam. What many
people do not realize is that it is illegal to remove from
Australia a fossil without consent from the government
agency responsible for land care/Conservation.
If the fossil is of significant value to AUSTRALIA as a
Specimen or a Museum wants it you are out of luck as far as
exportation goes. Once you start to carve a clam in order
to polish it you do risk lowering the value of the item.
Tricks are to follow the contour of the shell line or what
you consider to be the contour, Some have a sand type of
material mixed within the opal making it difficult to polish
once breaking through into this soft sandstone you may have
destroyed what value the clam had.
It takes time and many shells to gain the experience to know
just where to grind as if you do cut it wrong the value will
plummet. I have seen a beautiful Shell, all top Crystal
Opal, sell for over $300,000us.
Which would have been very Cheap, There are only so many of
these clams available, If you own one, Then consider
yourself lucky, there will not be many more produced.
In talking to miners these days, Clams are mentioned as, oh,
I only got 1 this year or I only got 15 or so this year, so
as you can see depending upon the miner and of course the
area being worked most obtain 1 to 2 figure quantities each
year only. Other opalised Turret type shells are talked
about in 1 every so many years.
Another item worth collecting from this area is the
belemites. These come in white opal, Honey opal, and Gem
crystal opal. Very pretty and make wonderful Jewelry items.
Again just as rare if not more so than the clams. The latest
find I had in Africa was an opal deposit where after carving
an egg shaped stone it was apparent that we were indeed
carving an egg, an opalised egg. It would be about the size
and shape of a hens egg.
Throughout the Australian opal fields from Coober Pedy to
Andamooka to Lightning Ridge to Quilpie areas there are many
different fossils of opal content. These are all rare and
well worth collecting as over time these can only but become
scarce and the value can only but increase.
And with this I want to introduce Ross Cranwick to the list.
Ross was a very early member of this list, and made a lot
of the early contributions. He lives in NZ and knows opals.
He left NZ and went to Africa to mine gems and is finally
back. Welcome home, Ross. Glad to have you back. hale
Subject: NEW: MK tile saw
About the MK-101 Tile saw featured in the LJ, Jan. 1999.
I looked up MK Diamond Products on the Internet, and
submitted a price request. The response I just got back is
shown below between dotted lines. (PS - it took about 10
minutes to get this feedback) Their web address is:
Thank you for responding to a very fine article on one of
Your request for a price quote is $ 1127 (suggested retail
price). The saw featured can be purchased at The Home Depot,
Lowes, Menards or many other fine hardware or ceramic tile
outlets. You will find the MK 101 purchased at one of the
above types of distribution can be slightly modified for
about $ 15.00 or less to be a more pleasing saw to use when
you are cutting rocks.
Please call me at 1 - 800 - 421 - 5830>>
I also used their links to get to Berland's House of Tools,
and got a price of $897.00 plus shipping.
Great saw for a bit of $$$$. There is also a model MK-660
(7" diamond blade) that sells a couple of hundred dollars
less. The one I'd like to find info on now is the MK-270,
for $279 at Berland"s.
That all folks.
M.G. Designs - Custom Handmade Jewelry, and Gemstones.
Subject: RE: Surface Tension
In news issue No.193 in MSG 2 there is a question about
surface tension and where to find a list of them. The CRC
Handbook of Chemistry and Physics in Section F defines
surface tension and lists many more than any lapidary would
want to know. The book is generally available in public
libraries. My copy is ISBN-0-8493-0466-0.
Subject: RE: Surface Tension
I checked my (somewhat old, but still a great reference)
copy of the CRC Handbook of Chemistry and Physics (check
any library) and found several pages listing the surface
solutions of chemicals. Water was listed at 73.05 dynes/cm.
If you can't find it there, call the chemistry department
of a local college or university.
Please visit our family web pages at
Subject: Re: Orienting Montana Agate for Cutting
Tom Harmon, of Crane, Montana, had an article in Lapidary
Journal some years ago about the different types of Montana
agate and orienting Montana agate for slabbing. I have
a reprint of it I got from him. It is the best information
Ive seen on the subject. He shows pictures of layered
dendritic, plumed, banded ribbon and other types and how
best to slab each type.
For starters, you candle your agate to see what is
inside. Use a bright lamp with a metal or opaque shade
(a mechanics trouble lamp is good) in a darkened room.
Wet the agate. Hold the agate under the lamp TOUCHING THE
EDGE OF THE SHADE TO THE AGATE so the light goes INTO and
through the agate, NOT so it reflects off the surface.
You can see some distance into the agate and make an
informed guess about whats there and how to cut it.
Mr. Harmon is a frequent contributor to LJ and R&G . He
may still have copies of the article. He is an expert
cutter and carver of Montana agate and has a great shop
with agate cabs, carvings, hand crafted jewelry, slabs and
rocks, really superb work. For the best word in
information Id get in touch with him at Box 94, Crane, MT
Subject: Re: Orienting Montana Agate for Cutting
Randy Aue asked about orienting Montana Agate. Get a light
bulb place it into a box to shut out excess light, cut a
small hole in one side of the box and hold the Montana
Agate up to the small hole in the box and roll it around to
view the inside of the agate. You can see the inside of the
agate in much the same way that egg inspectors candle eggs
to see if they are good in Grocery stores. You will be able
to see through the skin on the agate and tell where the
pattern is and where it would be best to cut.
Subject: Re: Orienting Montana Agate for Cutting
Try tumble polishing the rough - right on through to and
including final polish.
Candle (backlight) the polished stone with a high intensity
lamp. This should give you at least a reasonable idea
about correct orientation.
Subject: RE: Need Info on Diamond Polishing Belts
Hmmm, they do not sound like Diamond Pacific wheels. My
Titan came with DP wheels and they don't rust; I think
they're aluminum. I wouldn't think you could get expandable
drums and belts that could fit the Genie since they are
such small diameter and narrow wheels. I suggest you get
a hold of a DP catalog and check out their 6" wheels. I
think these would outlast any diamond belt on the market
and would therefore be more cost-effective.
Subject: Re: BIO of Margaret
Hello, Margaret, you will love this list! What types of
stones are you interested in? The area where you live is
full of beautiful stone to cut for almost any uses.
I live in Utah also, and come down from the north fairly
often just to visit relatives and collect rock! Maybe I
could be of some help, if our areas of interest connect.
Zion is so lovely, you are lucky to have the scenery as
If there is anything I can help with, just let me know.
Subject: RE: Lapidary Journal December Review
JR Schroeder wrote "December follow up teaser - For some
reason I couldn't talk my wife into letting me put a little
smoky quarts into her bread just for old fashioned fun. :)
Confused? Check out the December review or page 49 of the
Well, we'd better not try it in our electric bread bakers;
at least not mine! That quartz would be minced and it would
be a "treat" for all! LOL!
Have you noticed how much lapidary time is spent using
kitchen utensils? Microwaves, toaster ovens, dishwashers,
etc.? Anyone ever thought of a adding a second kitchen
instead of a second other room for faceting? <G>
What other kitchen things are used for gem treatment?
How about cutting? Would be fun to know!
Subject: RE: Which Oil to Use in a Slab Saw?
I read an article in Rock and Gem a year ago or so that
recommended using Anti-Freeze as a saw lube. I have used
it ever since and the only side effect I've noticed is that
the lubricant tends to foam up a bit. I plan on adding a
little rug doctor anti-foam (made for carpet machines) in
it which should take care of the problem.
I like using it because it cleans up easily and doesn't
smell bad. It is also inexpensive if you buy it on sale.
Has anyone had similar experience with it?
Randy: There is a file in the Archives of a letter by Bill
Ritter, who headed Contempo and who is very knowledgeable on
saws and sawing, entitled "My Saw Doesn't Cut", in which he
discusses oils and anti-freeze and blade life and so on. I
believe he knows his stuff, and believe what he said. You
can get a copy of the file; send a message to
firstname.lastname@example.org with the following on the subject
line: GET MySawDoesntCut.txt and enjoy! hale
Subject: Re: Questions about an Opalized Clam
That's something I never knew. I have always been told to
store opal in glycerin instead of water, as its best
medium, you say that that is wrong??
I know water will grow a scum after a while and have for
that reason mostly, stored my opal in glycerin.
I have never had a problem with the opal afterwards, it
still cuts good, and seems to retain its fire.
I would however like some more information on this subject
is there some place where I can find further Information?
I love cutting optical effect materials, especially Opals
and would like to maintain the highest quality in my
Subject: BIO: Kimberly Freedman
Good Morning and thank you for taking me in.
I am thirty eight years old and relatively new to this
hobby. I joined Santa Cruz Mineral and Gem Society in
1994, by 1995 I was VP and have just stepped down as
President over the last three years. I am now in charge of
the treasury which we boosted this last July by co-hosting
the Calif Fed of Min Soc Federation Show in Monterey.
My interests are broad. I started by taking a faceting
lesson from a jeweler in Scotts Valley. Then field trips
took me far and wide and I started cabbing, slabbing, and
tumbling. Recently, I have dabbled in some silversmithing
starting with some inlay projects and am struggling with
some design issues on a squash blossom necklace. I mostly
look for material I haven't seen anywhere else, then I tend
to hoard it waiting for "the perfect project".
I have a Pixie, a 6" Rock Rascal saw, a 12" Lortone saw and
a 24" Highland Park saw. I use acetylene with the Presto
system. Silversmithing tools come slow and sometimes
expensive so I only buy as I need or have made for me at the
tig/weld shop where I work. The club shop has cutting and
grinding equipment to fill in the gaps if need be and I am
a manager there on Saturdays.
I love field trips and Quartzite is a habit with me.
Mostly I enjoy the camaraderie and friendships I have found
over the years. I was fortunate to attend the CFMS Earth
Science Camp last September at Camp Paradise where I met
Dick and Janet Friessen (among others).
I work in Scotts Valley at Watkins-Johnson, Semiconductor
Equipment Group in Receiving and Materials Management.
Have been there five plus years and it gives me the freedom
to explore my hobby. The guys in the tig/weld shop are
always happy to fashion a bending jig or save metal scraps
or mend a broken bumper weld. They taught me safety using
the torch and helped patch a tumbler or two.
Don't think I'm going to make Quartzite this year due to my
recent separation/divorce but will be there in spirit. The
upside is I will be able to attend many more field trips and
club shows this year. I love to hike, hot springs,
photography, target shooting, gardening and cooking.
Kimberly Freedman (McKay)
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