melee ct weight

[whotheyare]

hey there I was wondering for melee stones set inside a piece of jewelry how can one accurately determine the total weight, they can see the diameter of a diamond but thats only a guess since you would need to see the depth of the diamond too to get an accurate weight? for example 2.5mm stone is 5 pointer but can a 8 pointer be a 2.5mm stone and can that be found out from an appraisor if the stone is already setin a piece of jewelry such as a cross?

thanks

 

[chrono]

For the setter, he/she would most likely weigh the diamonds before starting. For an appraiser to guesstimate the ctw, I suppose he/she makes an estimate based upon the size of the melees. If a person wants to be accurate, then the melees have to be unmounted and weighted, but the cost of unmounting numerous tiny stones, then remounting them would far exceed the cost of the appraisal (and possibly value of the jewellery item too).

 

[oldminer]

Melee can be reasonably well estimated by noting the diameter and the cutting style.
Diamonds can be deep (lumpy), well cut or spready, (thin). Deep diamonds weigh more than thin ones at a given diameter.
Diamonds may have very thin, medium or very thick girdles. The thicker the girdle, the more weight for a given diameter.
Diamonds may have no culet or medium or large culet. The more culet, the more weight for the diameter.
Diamonds may have small ,medium or large tables. Depending on other factors, this may also involve weight estimation adjustments for a given diameter.

I can estimate small diamonds pretty well, but it is an opinion based on a number of expert considerations. The best experience is having been a buyer of second hand items for many years and actually testing my ability to judge before actually putting the judgement to the test by destroying the item for the stones and finding out the exact weight, color and clarity. Few of us learn pain free. I had some very painful learning experiences several times over.

The real challenge is when one appraises an item with several hundred small diamonds set into it. One needs to be as careful as possible. If the appraiser is off .005ct per diamond on a 600 diamond piece, the error is going to be a whopping 3 carats. For five or ten diamonds .005 per stone is no big deal, but 3 carats off becomes a big deal. As the number of small diamonds increases in an item, the ability to make hard and fast judgements of weight gets worse and worse. There is no cure for this and we just keep this in mind as we create our opinion of value and content.