What do you expect in a precision cut stone?

[demantoid]

I'm curious what PSer's expect when purchasing a precision cut stone. Does precision cut mean there will be no windows? No tilt windows? No extinction areas? Or, despite the precise, exact mathematical calculations, could these things still be present?

Then, what about stones from award winning cutters? Are award winning cuts also precision cuts? Do you always expect excellent cutting from award winning cutters? Could an "excellent" cut still have a window or extinction areas?

These are just some questions that have come up as I look over my recently purchased batch of stones.

 

[pregcurious]

The stone is cut precisely, as in facet junctions meet, and there is a some type of definite pattern (e.g., symmetry in a round cut).

I don't think it always means a stone has no windows, or no areas of extinction. I try to assess each stone individually for what it is. As for tilt windows, I expect to see them to some extent, especially for low RI stones. I own both precision and what people call "native" cut stones. I appreciate both. My main goal is to have a beautiful stone with great color (subjective), and minimal areas of extinction. In terms of cut, if I look at the stone with only my eyes, and I see no window, and the cut does not look "wonky" (e.g. crooked), I am fine with it. (For certain truly rare stones, I would accept a wonky cut or window.) I won't pay more for a precision cut just to have a precision cut. Just a personal choice.

Here's a previous discussion from Rocky Talky. Although it focuses on diamonds, the points made are very good. It depends on the goal of the cutting.
[URL='https://www.pricescope.com/community/threads/precision-cut-what-does-this-mean.164265/']https://www.pricescope.com/community/threads/precision-cut-what-does-this-mean.164265/[/URL]

 

[minousbijoux]

I'm curious what PSer's expect when purchasing a precision cut stone. Does precision cut mean there will be no windows? No tilt windows? No extinction areas? Or, despite the precise, exact mathematical calculations, could these things still be present?

Then, what about stones from award winning cutters? Are award winning cuts also precision cuts? Do you always expect excellent cutting from award winning cutters? Could an "excellent" cut still have a window or extinction areas?

These are just some questions that have come up as I look over my recently purchased batch of stones.

What about these recent purchases - did they not work out for you? Did they turn out to be windowed?

 

[marymm]

My own definition of precision-cut means no windows (absent vendor description to the contrary) -- but as I understand it, even the most well-executed precision-cut stone may exhibit tilt windows and/or extinction/half-and-half-thing...

 

[chrono]

This is my definition of precision cutting:
Meetpoint accuracy
Superb polish
Correct cutting angles for best light return
http://www.osirisgems.com/precision_cutting

That said, not every lapidary is equally skilled and not all lapidaries have the same priority. Some go for a more balanced approach, some select perfection in cut (doesn't go for top colour or cut pieces with top colour) and some put more priority in colour (not the perfect cut in order to preserve best colour). Some lapidary also have more experience than others so those with lesser skill might select designs that aren't quite right and so the stone might show a tilt window easily or show more extinction than expected.