Find your diamond
Find your jewelry
shape
carat
color
clarity

Over Excellent Diamonds

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

mdx

Brilliant_Rock
Joined
Mar 1, 2002
Messages
570
Does anyone have any details or specs on the Japanese OE and OE2 cuts and in particular the princess style?
Regards
Wayne
 

Rank Amateur

Brilliant_Rock
Joined
Feb 26, 2003
Messages
1,553
Does anyone want to explain what the heck over-excellent diamonds are?


R/A <---- too lazy to google!
 

Rank Amateur

Brilliant_Rock
Joined
Feb 26, 2003
Messages
1,553
Next time I'm talking to my boss about getting a raise I'm going to describe myself as "over excellent".
 

mdx

Brilliant_Rock
Joined
Mar 1, 2002
Messages
570
Rich and R/A

The over excellent is mentioned in the March 7th issue of Rapaport diamond report under the heading Japan Market Report page 80

Basically the manufacturer Hohoemi Brains Inc. claims to have produced a cut far superior in terms of brilliance than the cuts we know.

If you cant find it and have some interest. I,ll type it out and post it.( Hate typing though)

Wayne
 

mike04456

Brilliant_Rock
Joined
Nov 20, 2002
Messages
1,441
----------------
Basically the manufacturer Hohoemi Brains Inc. claims to have produced a cut far superior in terms of brilliance than the cuts we know.
----------------
Yeah, and if I had a dollar for every time I've heard that claim attached to a new cut design or new branded diamond, I could retire tomorrow.


I'd be interested in more information myself.
 

slmulkey

Shiny_Rock
Joined
Oct 30, 2002
Messages
133
Ok, I found the company website...but it's not in English. They do have some pictures on there though if you want to check it out.

http://www.hohoemi.co.jp/O_E_cut.htm
 

Superidealist

Brilliant_Rock
Joined
Sep 10, 2003
Messages
655
Resurrecting this dead thread to add that I believe these are based on the Okuda cut. At least the patents cite Okuda and many of the ideas central to these (crown-to-crown rays, table-to-crown rays, calculated focal lengths, color enhancement through optimization of blue/purple fire, etc.) seem also to be present in the Okuda patent. These seem to have very odd proportions. I tried to run some numbers on the HCA but it wouldn''t allow the table sizes and pavilion angles.
 

valeria101

Super_Ideal_Rock
Premium
Joined
Aug 29, 2003
Messages
15,809
Date: 1/27/2005 17:29 AM
Author: Superidealist
Resurrecting this dead thread to add that I believe these are based on the Okuda cut
...I tried to run some numbers on the HCA but it wouldn''t allow the table sizes and pavilion angles.
So... what are these numbers ?
 

Superidealist

Brilliant_Rock
Joined
Sep 10, 2003
Messages
655
I don't remember all of them but I do recall one with a 38% table. I believe another had a crown angle of around 28 degrees. In general, they had shallow pavilion and crown angles and small tables. The HCA warned of fisheye on the one that I think it did take. From the patent illustrations it looked like there might be significant leakage under the table. I'll post more when I have time.
 

Superidealist

Brilliant_Rock
Joined
Sep 10, 2003
Messages
655
The US patent numbers for the O.E. round and the O.E. princess are 6694778 and 6818280 respectively. The Okuda cut is the second foreign patent cited in the O.E. round patent application. The Okuda cut was patented only in Japan. Interestingly, the patent for the Okuda cut is assigned to Hohoemi Brains and was issued in 2001 (application date was January 27, 2000). This is many years after Kazumi Okuda's death, so there must be an interesting story there.

Parameters for table sizes, pavilion angles and so on are contained in the patents but if you don't want to sift through it, it allows table sizes as low as 33%, pavilion angles as low as 37.5° and preferably no more than 40°, and crown angles satisfying the following inequality (around 31.5° for a 37.5° pavilion angle):

171.4883 - 3.74167pc ≤ 171.4315 - 3.75427p

where p is the pavilion angle and c is the crown angle.

The patents are over my head but maybe some of the people who really understand this kind of thing will find it interesting reading.
 

Superidealist

Brilliant_Rock
Joined
Sep 10, 2003
Messages
655
I thought I had one that worked in the HCA but found later that it had changed an angle on me. Every time I run one of these, I am warned of fisheye, a too small table, or danger of chipping from a too low crown angle.
 

Superidealist

Brilliant_Rock
Joined
Sep 10, 2003
Messages
655
Do Cut Advisor results extend to these kinds of diamonds?

For the numbers below, I assumed a girdle thickness of 2%. I don''t know how accurate that is, but adjust as needed. Here are some examples in the following format: Depth Percentage, Table Percentage, Crown Angle, Pavilion Angle.

59.44, 38.00, 31.60, 37.50
58.83, 40.00, 31.60, 37.50
58.21, 42.00, 31.60, 37.50
57.59, 44.00, 31.60, 37.50
56.98, 46.00, 31.60, 37.50
56.36, 48.00, 31.60, 37.50
55.75, 50.00, 31.60, 37.50

58.77, 38.00, 29.73, 38.00
58.20, 40.00, 29.73, 38.00
57.63, 42.00, 29.73, 38.00
57.05, 44.00, 29.73, 38.00
56.48, 46.00, 29.73, 38.00
55.91, 48.00, 29.73, 38.00
55.34, 50.00, 29.73, 38.00

58.15, 38.00, 27.86, 38.50
57.63, 40.00, 27.86, 38.50
57.10, 42.00, 27.86, 38.50
56.57, 44.00, 27.86, 38.50
56.04, 46.00, 27.86, 38.50
55.51, 48.00, 27.86, 38.50
54.98, 50.00, 27.86, 38.50

57.60, 38.00, 25.98, 39.00
57.11, 40.00, 25.98, 39.00
56.62, 42.00, 25.98, 39.00
56.13, 44.00, 25.98, 39.00
55.65, 46.00, 25.98, 39.00
55.16, 48.00, 25.98, 39.00
54.67, 50.00, 25.98, 39.00

57.09, 38.00, 24.11, 39.50
56.64, 40.00, 24.11, 39.50
56.19, 42.00, 24.11, 39.50
55.75, 44.00, 24.11, 39.50
55.30, 46.00, 24.11, 39.50
54.85, 48.00, 24.11, 39.50
54.40, 50.00, 24.11, 39.50

56.63, 38.00, 22.23, 40.00
56.21, 40.00, 22.23, 40.00
55.81, 42.00, 22.23, 40.00
55.40, 44.00, 22.23, 40.00
54.99, 46.00, 22.23, 40.00
54.58, 48.00, 22.23, 40.00
54.17, 50.00, 22.23, 40.00
 
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!

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