"Golden Tetras" or Cubic Grains and the Tetradecahedral

[Ray Rogers]

Anybody out there know how to describe a tetradecahedral grain?
or have a picture handy?

I can't seem to find one.

Ray

[Ray Rogers]

Anybody out there know how to describe a tetradecahedral grain?
or have a picture handy?

I can't seem to find either.

Ray

[Photo Engineer]

This is the closest I can get. You be the judge.

OTOH, if it is doable, why don't you make one? Then you can show us the pix.

PE

[totalamateur]

Groobled it.

[totalamateur]

PE's 14 sided crystals are prettier than mine, though.

[Ray Rogers]

This is the closest I can get. You be the judge.

PE

Actually, they do look like tetradecahedral grains to me.
Why are they marked "octahedra"?

Ray

[Ray Rogers]

Actually, they do look like tetradecahedral grains to me.
Why are they marked "octahedra"?

Ray

After thinking about my own question, I think I came up with an answer.
I will give it a try anyway.

Octahedral grain can be derived from tetradecahedral grain by continued ripening....

The grain in your picture were supposed to be octahedra...
but had there portrait taken before they were completely mature.

They were "toddlers"!

[Ray Rogers]

PE's 14 sided crystals are prettier than mine, though.

Thats true.

In addition, I am not sure they actually have the same structure!
There seems to be several possible shapes for a tetradecahedron.

Ray

[Rick A]

Did you try Googleing "photos of a tetradecahedron grain"? I think I saw a drawing of one once but I cant remember where. I think it was a patent for a silver halide grain for photography held by a japanese fellow. Hope that helped.

Rick

[Photo Engineer]

Octahedra = 8 sided, Tetra deca hedra = 4 10 sided. An octahedron in emulsion parlance in the case above is a cube with clipped corners. A cube has 6 faces and 8 corners. If you look closely at my photomicrograph, you see that each side has 6 edges but there are 8 + 6 sides making 14. Go figure!

There are several possible shapes possible. AFAIK, there is nothing "golden" or special about them.

PE