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[Eddie P]

This 4 inch sphere was not made by me but I'd be grateful for your thoughts.  Like a lot of the spheres (and eggs) coming out of the Congo in the 70s and 80s (I presume this dates from then) the shape is a long way from perfect.  Could a talented lapidary artist correct this now or does the banding and structure of the material effectively prevent it?  If you ground it perfectly round would you lose the integrity of the banding?

[irockhound]

I could see some ways to get it closer but I am not making spheres currently, and it would be a pain in my opinion so I will leave that to the many AMAZING sphere makers we have on this board.  As for the banding and structure you have no problem there.  This is good solid banded Malachite and it normally does not have weaknesses that would cause trouble in any way you tried to work with it.  Other Malachite where they use ground Malachite and Epoxy to fill voids and pockets is another beast but this isn't what you have here.

[Eddie P]

Irockhound, many thanks for this.  As I live in the UK rather than in the western US where most of you super-talented stalwarts of this site seem to be, I realise re-working this sphere is not something I can hand over. Sadly there are very few rock cutters over here  (we just don't have the mountain ranges and land is expensive).  But any thoughts from you guys are much appreciated.  Haven't yet made a sphere (don't have the equipment) but have cut and polished cubes and freeforms from imported roughs very happily so far.

[Sandsave]

It can be fixed, but it will end up about 3”-3 1/2”, that material is very soft, I have a jig I made that fixes the sphere heads in place, it has a adjustment to dial in each head as needed, you have babysit and take each head in as needed to round the sphere up.

[peruano]

I'd guess that you are saying that the sphere is out of round.  I've studied the photo and to my eye its within limits. Funny how our perception may be fooled (I'm expecting it to be round and my vision accomplishes that on the basis of one photo).  On the other hand occasionally you pick up a cab and are instantly drawn to a slight concavity or other symmetry problem and can remove it in the workshop without measurements or other aids beyond your visual perception.  In short its an attractive sphere.  My quick check of a dictionary produced the first definition as a body with one surface all points of which are equal distance from its center, but the second definition was a globe or globular body.  Your specimen meets the second definition.

[Eddie P]

Thanks both for your contributions.  Especially interesting to know that I'll lose a good bit of the volume trying to make it a perfect sphere, but nice to know it can be done.

[BlueWood]

I hear doing this material is quite a challenge.