Paging Rockdoc!

[flopkins]

Rockdoc - you posted the following in Mine''s thread about spinels -

Spinel might be a good candidate as well. Just have to be careful of extinction in them.

Rockdoc

What do you mean by extinction? Does the color fade? I have not heard of this before.

Thanks!!

 

[DiamondExpert]

...extinction refers to dark/black areas of no light return within a stone.

Spinel color does not fade.

 

[flopkins]

ah, thank you Gary!

I tried to search extinction and spinel and didn''t come up with anything useful!

would this be a property of the cut, ie like a ''window'' effect? or is it a property of stone itself that cannot be changed with the cut? (or both?!)

 

[riogems]

I believe this is a property of the cut.

 

[movie zombie]

does over saturation also cause extinction? i''ve seen some andesine that would have been lovely had it not been for extinction across much of the stone and i certainly don''t like my red to be blotted out by black! at the time i thought was caused by over saturation as well as poor cut.

movie zombie

 

[PrecisionGem]

Extinction is a result of cutting with incorrect angles, but it is much more noticable on a more saturated stone.

 

[movie zombie]

thanks!

movie zombie

 

[flopkins]

ah, thanks for the clarification Adam and Gene!

anyone got any pics to show what it looks like perchance?