Old mine cut: cut chart help: how does it measure up??

[familystone]

I was wondering how my stone measures up for a cut of its time. I have been told by the appraiser (Justin Krall) and multiple jewlers that it is a old mine cut stone however it looks more circular than cushion to me. I found the OEC cut chart on David Atlas''s AGA website. First I was wondering if I can use the charts if it is a more circular OMC?

Next, here are the numbers from the megascope: The stone falls into the 1-2 category in crown angle (36%), pavillion deapth (44%), and girdle thickness (4.1%). It falls into a cut 3 range (1st cat) on table perc. (45%) and crown height (20.3%) However it has a total deapth of 71.2 %

Any feedback would be welcomed

thanks,
Dave


oh on a side note I think I am going to set it in a leon merge custom setting

 

[JohnQuixote]

Date: 3/27/2006 7:07:28 PM
Author:familystone

I was wondering how my stone measures up for a cut of its time. I have been told by the appraiser (Justin Krall) and multiple jewlers that it is a old mine cut stone however it looks more circular than cushion to me. I found the OEC cut chart on David Atlas's AGA website. First I was wondering if I can use the charts if it is a more circular OMC?

Next, here are the numbers from the megascope: The stone falls into the 1-2 category in crown angle (36%), pavillion deapth (44%), and girdle thickness (4.1%). It falls into a cut 3 range (1st cat) on table perc. (45%) and crown height (20.3%) However it has a total deapth of 71.2 %

Any feedback would be welcomed

thanks,
Dave

oh on a side note I think I am going to set it in a leon merge custom setting

Hi Dave.

Is the culet open or closed? The OEC is more round than an Old Miner and tends to have a smaller culet. Both are beautiful cuts. It's hard to evaluate them using today's terms because they were cut to the natural rough faces of the diamond, not for specific angles or depth. It's like having a Model T Ford... If you value if for its history and beauty that's what is important. These stones aren’t at their best in modern lighting, but walk around downtown Disney under the gas lamps and you’ll be very pleased.

Here is a graphic from gemguides.com to help with categorization - though the culet on this OEC is drawn rather large... It may appear more closed (small).

 

[familystone]

John,

Thanks for the graph, the cullet it definately open however on the smaller side I believe. I have to dig up the megascope proportions again when she falls asleep to tell you the percentage on it. Anyways you can see it with the naked eye from the top but you do have to squint a bit. As for appriciating the stone for its history I definately do I guess I just got cuaght up a bit in the PS site and wanted to find out about all the stats on the stone even though it doesn''t really make a difference because its destination will allways be the same on my hopefully soon to be fiance''s finger.

Also, does age have anything to do with the difference of OMC v. OEC or is it just shape?

 

[JohnQuixote]

You're welcome Dave. Old mine cuts (derived from the Peruzzi cut) were common by the early 18th century and the old European cut was developed later, in the 19th century. It was more rounded, going in the direction of the round we know today. As mentioned, the shape and size of those old cuts depended entirely on the rough. The development of tools - like the diamond saw - allowed further evolution of the round brilliant by Morse, Tolkowsky and their contemporaries.

 

[valeria101]

Date: 3/27/2006 7:07:28 PM
Author:familystone

I found the OEC cut chart on David Atlas's AGA website. First I was wondering if I can use the charts if it is a more circular OMC?

I would think this leads to a more wild guess, but...Anyway, I don't think those charts are meant to be absolutely precise prediction tools about what diamonds look like - even when the cut style matches perfectly. So... I would not dismiss this one before getting to see it. Looks would be way more important to me than a rating based on proportions, especially since there are no hundreds and hundreds of similar old cuts to choose from. And then, the shape of these stones and individual looks should play a part - they are not 'standard issue' like round brilliants - so I would not just throw the dice to choose blindly among such stones.

Next, here are the numbers from the megascope: crown angle (36%), pavilion depth (44%), and girdle thickness (4.1%), table perc. (45%) and crown height (20.3%) However it has a total depth of 71.2 %
Any feedback would be welcomed

I can't tell precisely what this guy looks like, because real diamonds are never cut with mathematical precision - what you have is an approximate average of the real numbers. If the stone is not quite round, this makes the average even less informative. As is, with a very wild guess... it sounds good to me (with a DiamCalc guesstimate to back that up).

I would much rather have a picture than this. If you can take a look at the diamond, I doubt you'd need any pictures, since I can't see the real thing from where I stand, images taken in a controlled setup (IdealSCope, ASET) are allot more informative - at least for me that is. Seeing is believing

Oh on a side note I think I am going to set it in a Leon Mege custom setting.

 

[oldminer]

The chart applies to Old European Cut diamonds. These are round outline stones and NOY old Mine cut cushion shaped ones. Old Mine cushions can be very pretty, but I think they help to prove that you just can''t begin to describe all the possible appearances by simply using parameters. Screening old Mine cushions by parameters is probably a wasted effort. Old Euor cut round stones have much more consisten cutting styles and parameters can be used to screen them far better.

 

[familystone]

Thanks for all the feedback guys, as I said before it I beleive it is definately more round shaped the cushion thats why I was trying to use the chart.

I wish I could figure out how to get a good picture of the stone but as of yet I just can''t get one that isn''t blurry. Maybe I need to buy a loupe and put it up to the camera lens. I tried fooling around with the macro setting and that hasn''t worked out for me yet.

 

[valeria101]

Date: 3/28/2006 12:43:04 PM
Author: familystone


I wish I could figure out how to get a good picture of the stone but as of yet I just can''t get one that isn''t blurry.

Another idea... get an IdealScope and tell us what you see. No pictures really needed (cool, but hard to take - some pricescopers managed though).

 

[roxy7]

To take a clear picture, switch the setting to "macro" on your camera. My bf found it by fiddilng around with his.

As far as the quality of an Old Mine Cut, look for symetry and examine the girdle to see if it is chipped. Honestly, those are two of the mort important things dealing with the quality of an old stone.

When Leon looked at our OMC, he commented that it was a beautifully cut OMC. By that (since we had no measurements, etc), I think he just meant by the overall symetry of the stone and the lack of chips and wear and tear around the girdle of the stone.

 

[familystone]

Roxy,
no chips in the girddle but there is one microscopic bit of "skin close to the girddle and the symetry seems good

-Dave

 

[roxy7]

Congrats