Can we figure out the cut on this diamond?

[Frumasring]

Hi everyone,

I was just given what I think (?) is maybe an antique diamond. This was my grandmother’s first marriage e-ring now set into a necklace. Marriage was in 1930s. I’ve tried taking a few pics, all are horrible. To me, not an expert, it looks like a MRB but could this be in 1930? I’m not sure what I’m going to do with it - set it a different pendant setting, maybe with a milligrain bezel (if it is antique wouldn’t that compliment it) or buy a similar stone and make studs. Looking for opinions on cut and would welcome ideas on settings!

 

[tyty333]

Early round brilliant...

 

[Frumasring]

Early round brilliant...

Is this the same terminology as transitional cut?

 

[DejaWiz]

Is this the same terminology as transitional cut?

No, it looks like an MRB/RBC...they've been around for a long time, but Tolkowsky figured out the ideal proportions and angles for maximizing light return in the 1910s.
Yours appears to have a steep pavilion angle (I'd guess 41.4-41.8 ) and a larger table (I'd guess 60-63%)
That pendant looks fantastic!

 

[Karl_K]

Have they been tested as diamond?
Any stamps on the back?
I would recommend having a professional take a look in person then an appraisal if needed.

 

[Frumasring]

No, it looks like an MRB/RBC...they've been around for a long time, but Tolkowsky figured out the ideal proportions and angles for maximizing light return in the 1910s.
Yours appears to have a steep pavilion angle (I'd guess 41.4-41.8 ) and a larger table (I'd guess 60-63%)
That pendant looks fantastic!

Thanks for the info! I’m not sure how to interpret the numbers but would these mean this is a well cut ERB as opposed to a poorly cut? There is a lot of fire in this stone, I’m just a crap photographer.

 

[Frumasring]

Have they been tested as diamond?
Any stamps on the back?
I would recommend having a professional take a look in person then an appraisal if needed.

Just 14K on the setting. I’ll be taking the stone to my local jeweler this weekend, just wanted to figure out as much as I could before going in!