Putting the new Tolkowsky line to the test with the HCA

[Dr_Smith]

Yesterday, I went to Kay jewelers, who have a new line of diamonds (as of last week): the Tolkowsky line. They are touting that their diamonds meet the Tolkowsky standards and are more brilliant than their Leo diamonds. Furthermore, only Sterling Jewelers, Inc. (who owns Kay's) has access to the Tolkowsky line.

So, I asked to see one, and she brought out a stone that was an I color, SI2. All of the other stones seemed to be significantly lacking in color/clarity as well, which concerned me for their "top of the line" diamonds. Anyway, I whipped out my mobile phone to bring up the HCA. "What are you doing?" she asked innocently. "I'm going to input the dimensions of the diamond into the Holloway Cut Advisor algorithm to verify the Tolkowsky criteria," I replied (while fighting an inward sense of smugness). I knew what was coming... she was about to be schooled.

She blinked.

So, I explained about Tolkowsky's 1919 thesis, the critical reflection dimensions, ray tracing, etc. I opened up Skyfire on my Windows Mobile phone and brought up the HCA I had bookmarked. "Now I just need this diamond's dimensions, please."

"Uh... well, sir, these diamonds are IGI certified and all we have are the dimensions in millimeters."

Well that caught me off guard, because I hadn't practiced converting the mm dimensions to the %'s needed for the HCA. Also, I had no idea about the crown and pavilion angles. At this point, I put away my phone and started to question the quality of the stones.

For starters, why were they all <H in color and <SI1 in clarity? She didn't know, but she did say that these IGI stones were color graded from the top down... which gave me pause. "I thought diamonds were color graded from the side, because a well cut diamond will appear more colorless when viewed from the top?" But she didn't know the answer. I assume the jeweler already knew this, which was why the Tolkowsky line was already in mounts, and not loose stones.

After examining a few of their "SI1" stones that looked more like SI2/I1 stones, I put away my loupe and thanked her. I'm not convinced that the Tolkowsky line is going to do so well, except to the uneducated. But I am interested in learning if anyone has viewed these diamonds in other cities?

**edit: I forgot to mention that she had a GemEx card that showed fire/brilliance/spread... but that was it.

 

[stone-cold11]

Actually you cannot calculate anything from the dimensions other than the % depth, which is the total depth divided by the width multiplied by 100.

 

[Lula]

The stones you saw weren't "Cut by Tolkowsky" brand stones, were they? http://tolkowskydiamonds.com/?
Because your description of this "Tolkowsky" brand doesn't seem at all like what I saw when I viewed the Cut by Tolkowsky diamonds a few weeks ago in a local store (not a Kay's jeweler).

 

[Dr_Smith]

I believe they were just diamonds cut to the Tolkowsky ideal standard... but I'm not convinced because they wouldn't give me the full dimensional specs.

 

[Lula]

I believe they were just diamonds cut to the Tolkowsky ideal standard... but I'm not convinced because they wouldn't give me the full dimensional specs.

Yes, I agree, it sounds like they are just using the Tolkowsky name for their house brand, without supplying any of the stats to back up their claim that their diamonds are cut to Tolkowsky specs. I'm surprised the Tolkowsky family doesn't do more to protect the use of their name. But perhaps "Tolkowsky" is now a generic word in the diamond industry?