Carving jade
jand...@asc013.ets.ford.com
When I asked about getting some onyx custom carved, I got a suggestion to try
using "diamond points" in a Fordam or Dremel, and carve jade instead.
That sounds cool, but I've got some more questions...
1) What speed should diamond points be run to cut jade?
2) What kind of finish will cutting like this produce? If the finish is rough,
how do I polish it?
3) What kind of lubricant ( if any ) should I use?
4) How tough is jade? Will it take being carved into a shape with 1/2
spikes, or will such a feature be too fragile for wearable jewelry?
5) Is there anything toxic about cutting jade this way that safety glasses
and a paper dust mask won't provide protection from?
6) Where can I buy jade to cut, and is there anything I should look for, or
look to avoid in a piece of jade?
7) Are there any other questions I should ask, but haven't because I don't know
enough to know the answer is important?
Thanks for your patience.
As you can tell, I'm a silversmith, not a gem-cutter :-)
John
John F. Miller
with carving jade.
In article <940801180...@asc013.ets.ford.com>,
<jew...@mishima.mn.org> wrote:
>1) What speed should diamond points be run to cut jade?
You might get a definitive answer from someone like Lapcraft Company
(614) 764-8993 or from an advertiser in Lapidary Journal. My approach
would probably be just to experiment with it until I found what seemed
to work for me.
>2) What kind of finish will cutting like this produce? If the finish is rough,
> how do I polish it?
Polishing with finer grades of diamond is probably the best route to take.
Both jadeite and nephrite often have interspersed hard and soft areas
and tend to undercut, giving a classic "orange peel" appearance. Cutting
and polishing with diamond reduces undercutting significantly.
>3) What kind of lubricant ( if any ) should I use?
Water is probably the best all-around lubricant. Jade can be sanded
dry with silicon carbide, but the dust is a potential health hazard.
Diamond tools should never be run dry, as excessive heat will cause
their premature demise.
>4) How tough is jade? Will it take being carved into a shape with 1/2
> spikes, or will such a feature be too fragile for wearable jewelry?
Jade is extremely tough. As long as a piece has no detectable fractures,
it will probably take just about any degree of fine detail.
>5) Is there anything toxic about cutting jade this way that safety glasses
> and a paper dust mask won't provide protection from?
The only hazards I'm aware of are those of fragments getting in the
eyes and dust getting in the lungs. Safety glasses, a dust mask, and
keeping the work wet (to settle the dust) should do the trick.
>6) Where can I buy jade to cut, and is there anything I should look for, or
> look to avoid in a piece of jade?
Check the ads in Lapidary Journal. Color, fine grain, and absence of
fractures should be your primary goals in selecting rough. Good jadeite
comes mostly from Burma (Myanmar) via China; jadeite from California
or Guatemala tends to be dull in color and not very interesting. Nephrite
is available in a much narrower color range than jadeite but comes from
more numerous sources -- British Columbia, Wyoming, California, Alaska,
New Zealand, Lake Baikal area, etc.
>7) Are there any other questions I should ask, but haven't because I don't know
> enough to know the answer is important?
Just try to be sure that you are actually buying jadeite or nephrite
and not a substitute material. The best way to do that, short of learning
enough gemology to test the material yourself, is to buy only from a
good reputable dealer who specializes in jade. Again, check the Lap.
Journal ads.
John Miller, Gemcutter/Graduate Gemologist/Analyst Programmer
j...@med.unc.edu
--
John Miller (John_...@unc.edu)
Department of Pharmacology, UNC-CH School of Medicine
1026A FLOB (231H) CB#7365, Chapel Hill, NC 27599 Tel: (919) 966-6966
Steven Speer
I've been trying to get questions like your answered here as well with
no luck. If you receive any replies via e-mail, I'd sure appreciate a
copy. Otherwise, maybe we can educate each other?
-Steve
21012d
1. working speed for diamonds on jade
For the points I generally run at the max click of the dremel tool
(25,000 ? 30,000) The most important thing is to develop a technique
to keep it cool and lubricated (pt 3) with plain water. The one
that works for me is dipping and having water on the stone surface,
others set up drippers, you then touch and release over and over,
Never put much pressure and never keep the pressure on for even
a full second. After you have done it once or twice you can
see and wince when the cut changes color and you realize "no more
diamond on that surface"
2. finish is fair, for some of the tools you can get different grits.
I have not used them enough to have an opinion but the more expensive
sintered bits may give a better (but still not polished) surface.
for polishing, there are several approaches, you can use diamond
compounds (in oil base in syringes) with wood, leather or other
home made tools, tooth picks can work, some kinds of bamboo skewers
work well (put compound on the peice, not just the stick)
you can buy kits of diamond polish pads. I have not used it enough
to know how much better this is then one.
(aside backing up, for diamond core drills, follow manufactures
recomendations...very small ones can go at slower dremel tool speeds,
by a 1/4 inch you are down to low drill press speeds. )
A different approach to for polishing which works for some
situations is to run a load through a small tumble polishing
run starting with fine grit or prepolish. This will destroy fine
edge details and sometimes you get significant reduction on edges
without getting effect on deeper cut in places or interior cuts.
I have had fair success with this for flat but intricute dangle
peices...some inner edges are not polished but the outside ones are
nicely rounded with no hand work.
You may want to read up a litte bit about jade, there are two
very different minerals (or three)accepted as jade, nephrite is the
tougher (and better IMHO for carving) but it has two common
characteristics which lead to polish problems. It is very common
to have very soft carbon patches, in lots of British Columbian,
Alaskan and Siberian these appear as black flecks. It is also
possible to have many other things as inclusions such as chromite,
all of these lead to variations in the surface which cause polishing
problems. Second, Nephrite has a microstructure of twisted interlocking
crystals, and again the surface is not of uniform hardness.
This gets into 6 and 7 issues, there are lots of differences in
quality, from material not worth a dollar a lb to fine cabachon
"Imperial" jade worth a thousand dollars for one cut stones worth.
It is not impossible to get good rough, that can be polished well
in the 20 dollar a lb range (or maybe I was just lucky) Some
Black Wyoming material will take a mirror finish easily, some will
still have surface problems now matter what you do.
3. good lubricant is water...this helps a lot for 5, don't
make dust, make mud and then get rid of it.I do not have
good information about its toxicity, the most common colorant
element is chromium which is toxic, its a distant cousin
and found associated with asbestos.
It is a silicate and high speed grinding can produce dangerous dust,
keep it wet and wear the mask is my advice.
4. As a generality, good nephrite is one of the toughest of stones,
you could definitly do ear ring dangles with loops or points much
smaller than 1/2 inch... I have made (a few dozen with one returned
for a break in normal use) ones from a thin sliced slab (less than 1/8
inch thick) (1/16 did not work :-)) with S shaped hook like shapes
of about 1/8 inch. Jadite is not as tough but I have made 1/8 thich
dangles there but the main body was a 1/4 or so with just small
projections 1/8 or less. One "I am still learning" and always will be
issue with some jade is that it often looks like it has ugly dangerous
fractures and yet be extreamly solid. On the other hand some
Alaskan stuff (from first hand experince) has invisible fractures
and some of the light green Siberian nephrite is sort of crumbly.
6. Where to buy Jade. I have picked up bits and peices at shows
and have dealt with two Mail orders both advertisers in Lapidary
journal. Bergstein or (?sp) Berstrom Jade sometimes has some
excellent material and sometimes can cut to order (like my thin
slabs) ...I forget the others name, they had an Alaskan address and
claimed to have secondary access to a claim operation. I got
what I asked for, delivered promptly and was disappointed.
7. Other issues, the big one is Jade vs Nonjade vs Enhanced stuff.
There is a lot of material, some in same mineral families some
not which comes up being sold as Jade, very common are softer
(and weaker) hard serpentines. These are reasonable carving stones,
but IMHO not for jewelry.
It is worth noting that both Jades are softer than quartz which in
some folks opinions makes it unsuitable for some (hand wear) jewelry,
they are both harder than steel so you can eliminate most serpentiens
with a scratch test. Beyond that, find trusted sources or do not
pay more than you would risk being wrong about.
Not relevant if you are buying rough but perhaps as you look
and when you make something, most jades polished or near polished
surfaces have an affinity for oils and wax, cheaper (or honestly
problem surface polishes) can be waxed or for small objects rubbed
on the skin (nose) to look just a little better.
Good luck. Try Jade
Mr. Les DeGroff