Question on names of facets for fantasies

[Sergey Savrasov]

Hello, everyone.

My question is about names of crown main facets for fantasy rounded cuts of diamonds like Marquise, Oval, Pear.
Mostly question is directed to cutters and gemologists of labs but I will be glad for any information.
There is profile of marquise with three types of crown main facets.


What are names of given on picture types of facets (under numbers 1, 2, 3) in different countries? I understand that we can call them crown main facets but how is it possible to separate these facets by names?
In practice I heard of different names of these facets. For example (see on picture),
1st type - main crown facets.
2nd type - point crown facets, nock crown facets.
3rd type - wing crown facets, side crown facets.

What are your opinions about the names?

 

[diagem]

They are ALL considered Main Crown Facets, isnt life difficult enough??

Why invent names? It will make the allready difficult task of comunicating between manufacturers and the actuall cutters even more confusing...

Dont you think?

 

[Sergey Savrasov]

I try to explain my question in detail.
At first I would like to say that I need this information for indication of facets in the reports of stones for cutters during work with semipolished stones or stones which need recutting. In the report it is necessary to show angles of different types of facets.

Many names are spread and it is hard to find names which everybody can understand clearly. It may be connected with fact that professional cutters rarely talk with each other about professional subjects and that''s why unified terminology isn''t appeared.

I have wrote in the forum for consumers hoping that experts use more canonical names.Also I hope that somebody from cutters could reply me.


To DiaGem:
I think, different names are necessary to mark out different facets by symmetry, by proportions, by final estimation. Different types can have strongly different angles and it is not bad, just angles of facets inside one type should have similar angles for good appearance.
Separation of types helps communicating between cutters. For example cutters will easily understand which type of facets should be corrected after measurement of proportions by scanners if correction is necessary.

For RBC all crown main facets are similar and they have only one name. But crown main facets of fantasies are different and they should be separated in different types.

 

[JohnQuixote]

Sergey, I asked Brian Gavin for his input.

Because a Marquise is irregular in shape we use different names to point certain facet positions. Here is the reason: Unlike a round cut where crown facets retain the same indexing - in a marquise the grain pattern of the rough will change the shape and this pattern is seldom consistent… What is a top corner in one may be a bezel facet in another.

So, use of names for crown facets is mainly for cutting and polishing purposes. The main pavilion facet will retain the same position as the main crown facets. Of course, there may be different names form different cutting centers in the world - so further input will be welcome and of interest.

(Brian says he hopes you don’t mind his “MarqOval” drawing)