[Rockhounds] sphere-makers: how do you make very tiny spheres?

[DonH]

Jim Murowchick wrote:
> I found the article (2 actually) for the sphere maker:
> 
> Sunderman, Harvey C., (1970) Refractive index determination by orientation
> variation.  1.  Uniaxial crystals.  American Min., 55, pp.1405-1415.
> 
> He also refers to Bond, W.L. (1951) Making small spheres.  Reviews of
> Scientific Instrumentation, 22, p.344.


Magnificent and delightsome!  The first article is on line of course, 
and that is exactly the kind of thing I've heard about.  I also found 
the main topic of the article quite interesting.  I will eventually make 
one of these--there is a chance I may be moving yet again, since I have 
been recruited for a more substantial position in another state, but I'd 
like to make one soon.

I could order the second article through the research library at work, 
but would appreciate if you could get a copy.

Now that you've shown this, it jogs the dusty cobwebs of my memories, 
and I remember someone describing something like this to me long ago, 
using nylon stockings as a mesh cover.

I'm going to do this right, and will post the results.  I would imagine 
the chamber can be made of almost any hard, modern material, including 
Delrin plastic or brass.  I would probably want to make more than one 
chamber, each lined with a succession of 400, 600, and 1200 grit 
self-adhesive polishing paper (I can get that from Buehler).  I can find 
brass 40 micron mesh cloth to use as a cover material.

Indeed, these are intended to be used with an refractive index immersion 
liquid.  This is a great way to teach orthoscopic and conoscopic 
observation of minerals.  Using a sphere solves two problems: it 
provides a smooth surface to view, and it takes away any structure that 
might distract the novice from understanding that the optical properties 
are not necessarily tied to the morphology.

I'll send the plans for this to someone who can cut the chamber, and 
we'll get started.


Thanks again!

best,
Don