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Tumble polish Larimar?

Hi all!

I have the opportunity to purchase some small chunks of larimar that
I’d like to try tumbling and drilling to use as freeform beads. I’ve
never done any sort of rock tumbling before…I only use my tumblers
for jewelry! I have a brand new vibratory tumbler that I’m using
right now for my jewelry and a plastic rotary tumbler that I used
until I got the new vibratory one.

I’d like to try using the old plastic rotary tumbler to tumble
polish these larimar chunks. Can anyone help me figure out the best
way to do this? What grits/polishes should I purchase? Also, I have
a Dremel in a drill press…would that be suitable for drilling the
holes?

This is a whole new area to me and any help would be most
appreciated! Thank you!

Karen Tremblay
KaeLynn Jewelry Design
Timmins, ON
(705) 360-5861
www.KaeLynnDesign.com

Karen, I have looked for a reply. Finding none I am writing to
comment that I have purchased Larimar jewelry on St. Thomas and what
I have been able to read about the stone is that it is not used for
rings, often, because it is a very soft stone. My concern in tumbling
would be that you need to be careful about the media you use.

Eve Welts, Certified PMC instructor.

Try tumbling in ground walnut shells, you can get them at PetsMart
as some kind of bird litter. It works for me and the air forces
requires the stuff for “sand” Blasting certain components.

Jerry

Hello Eve,

    I have been able to read about the stone is that it is not
used for rings, often, because it is a very soft stone. My concern
in tumbling would be that you need to be careful about the media
you use.

Thanks for the reply. I’ve actually never tumbled anything, so I
don’t even know where to start as far as media is concerned. I did
a bit of searching on the net and found a couple of “grit kits” for
tumble polishing. I knew about the softness…I just figured that I
would check the stones every couple of hours or so on the coarsest
grit. Do you think that might work?

Karen Tremblay
KaeLynn Jewelry Design
Timmins, ON
(705) 360-5861
www.KaeLynnDesign.com

Hi Jerry,

    Try tumbling in ground walnut shells, you can get them at
PetsMart as some kind of bird litter. It works for me and the air
forces requires the stuff for "sand" Blasting certain components. 

Are you saying that I would use only the ground walnut shells as a
tumbling medium? or would you start with the coarser grits, work
your way up and then use the walnut shells as a final polishing
step?

I’ve never tumbled anything, so any advice is very much appreciated!

Thanks!

Karen Tremblay
KaeLynn Jewelry Design
Timmins, ON
(705) 360-5861
www.KaeLynnDesign.com

Personally, I wouldn’t try anything until you check with someone who
knows Larimar well. It is a rare, soft, pectolite. It is quite
special because there is little left to mine, as I have read. I
certainly would not think coarse grit should be used, if at all, for
long. However, I’ve been unable to locate instructions on tumbling
it, also. I would do nothing until you have found someone who knows
what to use. You might call Rio. They are usually extremely helpful
about what media to use for tumbling. The number is: 1-800-545-6566.
Often one of their tech people reads Orchid and I hope would make a
comment here.

Eve Welts

Larimar is one of my favorite stones and very tricky to work with. It
is extremely sensitive to vibration and I have had it disintegrate in
my fingers while grinding. It will also crack easily and find working
with it similar to grinding opal, fragile. Another source for
is Lariamber.com which is a larimar and amber mine in
the Dominican Republic. Mr. Hermann Dittrich may be able to help you.

Beth Thompson

Hi,

I work some with Larimar.

I cut it with a diamond blade on the hanging motor or diamond
slabbing machine. Then if you want to polish small carved pieces, I
grind the most off with a Mizzy wheel and then to finer diamond
wheels/burrs. The stuff takes a polish really easy. I use a sanding
mandrel with 220 grit sand paper, then to 1200 grit and then
polishing paper. That gives it a good bright shine. Then I use
50,000 grit diamond mixed with olive oil on little a felt buff to
bring it up to ‘water polish’. The stuff is easy to work and has got
the same feel and easiness as opal. It can be put into rings and
those pieces should be handled the same as say, a Tanzanite ring.
Living in the Caribbean, I love this material, since the very best
quality has the same color as the sea outside my workshop. Keep in
mind the old saying concerning any material, namely, rubbish in,
rubbish out! Don’t work in lousy material if you can.

Tumbling won’t be a problem, if care is taken. Larimar has a
tendency to split along the white/blue lines but I figure that if it
split during cutting and polishing, that’s good because better
sooner than later. Within reason, I have not found it to be heat
sensitive but while the heavy cutting or grinding takes place, it is
quite shock sensitive. That is good, because I want to subject my
work to extremes before I sell it. I have faceted some material for
fun and I used a phenolic lap with Linde A. Without having tried it,
I’m sure cerium oxide or diamond would work as well on a lap.

Good quality material is not cheap, and I find it surprising that it
is often set into badly made silver jewellery .I only set it in 18ct
gold. For some pictures of finished work, go to my website and they
on the first page after the enter button.

Cheers, Hans Meevis
http://www.meevis.com

 Personally, I wouldn't try anything until you check with someone
who knows Larimar well. It is a rare, soft, pectolite. It is quite
special because there is little left to mine, as I have read. I
certainly would not think coarse grit should be used, if at all,
for long. However, I've been unable to locate instructions on
tumbling it, also. I would do nothing until you have found someone
who knows what to use. You might call Rio. They are usually
extremely helpful about what media to use for tumbling.= 

Hello Eve and all,

Ooooo, yikes… I have never tumble polished this stone and I have
not had good experiences using traditional lapidary techniques
cutting and polishing Larimar. I’ve been doing lapidary for 20 years
but I’m still considered a rookie in some lapidary groups :o).
Needles to say it’s not my favorite mineral to work with. As for
tumble polishing, experimenting will be in order, but that’s the rub,
limited amount to work with and it’s not cheap. From what I can
remember the matrix is harder than the parent mineral? I would think
that if there is not too much matrix it should be pretty consistent
in tumble polishing, but I experienced A LOT of cracking and chipping
when I was cutting and grinding it. When tumbling make sure your
pieces are similar in size as the bigger pieces may beat-up the
smaller ones. I would use the traditional 4 pack tumbling charge kits
just about everyone sells, we carry one on page 279 of our tools
catalog.

Sorry, not much help.

Sincerely,

Thackeray Taylor
Rio Grande Technical Support
800-545-6566 ex 13903