Find your diamond
Find your jewelry
shape
carat
color
clarity

Fisheye and Nailhead

Status
Not open for further replies. Please create a new topic or request for this thread to be opened.

pyramid

Ideal_Rock
Premium
Joined
Nov 10, 2002
Messages
4,607
An aquaintance has a ring which I can see the girdle through the table, I can also see that the table of the stone is very dark when someones head is blocking the light. Is this a fisheye and a nailhead. Is it possible to have both these features on ONE diamond? The bottom pavillion facets also seem to show beside the star facets in some lights. It does not seem to be a well cut stone but I ofcourse would never say anything to that person. The table also seems to be big on the diamond.
 

Garry H (Cut Nut)

Super_Ideal_Rock
Trade
Joined
Aug 15, 2000
Messages
15,650
Well done Pyramid


Fisheye's are too shallow and also direct a lot of the light toward the oservers head, just as a very deep diamond does. Sergey calls them Shallow nail heads. you can read a lot about this at www.cutstudy.com - there is an article by Bruce Harding (Beryl) there with a simple explanation and ray paths etc that he wrote in the 1970's.
 

Serg

Ideal_Rock
Trade
Joined
Mar 21, 2002
Messages
2,535
----------------
On 3/31/2003 6:59
0 AM Cut Nut wrote:

Well done Pyramid


Fisheye's are too shallow and also direct a lot of the light toward the oservers head, just as a very deep diamond does. Sergey calls them Shallow nail heads. you can read a lot about this at www.cutstudy.com - there is an article by Bruce Harding (Beryl) there with a simple explanation and ray paths etc that he wrote in the 1970's.
----------------
Garry,

Fisheye's do not depends from crown angle.
Shallow nail depends from relationship between Pavilion and crown angles.
I never said that Fisheye's diamond must have Shallow nail.
It can only.
 

ociopia

Rough_Rock
Joined
Feb 9, 2003
Messages
95
I don't know at all what the "fisheye" or "nailhead" is but now I'm wondering - I have seen a number of 2 carat+ rb's that look like they have "big, open holes" for a table with very little light action. Definitely "spready." Is this what you all mean or is this something else entirely?

Sherry
 
Status
Not open for further replies. Please create a new topic or request for this thread to be opened.
Be a part of the community It's free, join today!
    Horses for Courses: Polo Match Jewelry
    Horses for Courses: Polo Match Jewelry
    An Excellent K Color Graded Diamond
    An Excellent K Color Graded Diamond
    Astounding AVR
    Astounding AVR

Need Something Special?

Get a quote from multiple trusted and vetted jewelers.

Holloway Cut Advisor



Diamond Eye Candy

Click to view full-size image.
Top