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[Phishisgroovin]

I need some pointers.
My High School buddy has a nice slab of Larimar he wants to work on my machines.
I would like to help him make a matching set for his lovely wife.

What polishing steps should i need to learn about with larimar?

Heat on buffing? No heat on shining it?
what are the do's and dont's to get a glassy shine?

[55fossil]

   I have only cabbed a few pieces of Larimar...   The chalky matrix is super soft. I started by sanding with a 280 grit wheel with a lot of water. The best piece I had was solid and seemed to have a good silica content. Still cut easily but needed to be done very slowly.
   The other pieces were a nightmare!   The white veining was very soft. Even the blue areas were chalky. It was easy to break the pre-form if you worked it too hard and with any amount of pressure. It was easy to tell this was low grade material just by the feel of the Larimar and a lack of silica. I hope your piece feels heavy and is full of silica.
   The good piece took a good polish with a wet leather buff and alumina oxide, no heat.

[ileney]

I took a short lapidary class with Michael Boyd and he helped one of the students back her larimar with jade, like with an opal doublet. He said larimar is known to be prone to fracturing and instability unless reinforced or protected.

[Redrummd]

Step one - grab the Hxtal.....

[Greg Hiller]

My biggest suggestion is to stay away from steel grinders.  Use a coarse grit drum sander with a new 220 grit belt.  Larimar is not very hard.  It is super sensitive to impact.  I suggest backing the stone with a thin piece of some other stone (epoxy to back).  Getting a high polish with this stone is not difficult.  As I recall cerium oxide on leather worked very well.  In general you just need to be super patient with this stone.  Don't be in a rush or your stone will end up 1/2 the size you planned. 

[gemfeller]

Having heard stories about how difficult it is to cut without fracturing, I've never bothered with the stuff.  It raises a question in my mind: if it's that fragile during cutting, how does it stand up to use in jewelry?  I'd think rings would be a problem with the kind of sectional parting described upthread, and closing bezels on cut stones would seem to be tricky.  Yet it seems to be a hot item in jewelry.  Any comments based on actual experience?  Maybe backing as has been mentioned serves to make it durable enough?

[finegemdesigns]

Don't cut any shapes with pointy corners. Rounded shapes like circles or ovals are safer.