Cut Nut: Can HCA be used to "Grade" stones?

[Manks]

I have been playing about with the HCA, which says:

A score below 2 (Excellent) means you have eliminated known poor performers (more than 95% of all diamonds). Your own personal preference may be for a diamond with an HCA score of 1.5 more rather than one with a lower score of say 0.5.

Can the tool be used more extensively, for example to say that 1% of stones score 1.5 or below, 5% score 2.0 or below 15% score 3.0 or below?

 

[Garry H (Cut Nut)]

It sure could manks.

You just got yourself a project

Get all the crown, pav and table sizes on all the worlds diamonds!!!
Start a data base.

I make the estimate based on the rejection rates in my business experiance.
I think since then cut quality has improved and probably 90% of all round brilliants might come in under 2.

Part of my mission is to get all labs to put angles on reports. I am pleased to say that 1 very major player has agreed and is beiginning to impliment this over their range of reports.
At an appropriate time I will make an announcement about this

It will increase dramatically the diamond availability in the cut quality concious market.

 

[valeria101]

In the meantime, Jonathan has put up a little H&A search engine with a few choices there. I am wandering where are those stones from (Just their selection?). There are other places with simmilar options... but not oo many.

 

[Manks]

Cut Nut

When I have a spare 25 Million years, I will glady give you a hand with the database.

Something else occurs to me. You call yourself Cut Nut, not "The 4 Cs Nut", granted, but maybe you could include clarity and colour in the tool and it could then give the stone an "overall grade". I suppose you wouldn't be able to include weight as it is not a quality measure per-se.

So, when you have a quiet weekend perhaps you'd be so kind as to...