gem sizing

[theresa]

I recently bought 3 Rubies at 3.75mm but when I checked the sizes they were 3.38 to 3.43mm. Is this a normal tolerance or should I complain?

[Aurarius]

I recently bought 3 Rubies at 3.75mm but when I checked the sizes they were 3.38 to 3.43mm. Is this a normal tolerance or should I complain?

I can understand your disappointment. Before you assume the worst, was the advertised measurement of 3.75mm qualified with a phrase such as "measurements approximate"?
Have you taken measurements from different points round the stone edges, and the figures you quote above are the lowest and highest maximum readings?
What measuring tool are you using?

[Gemsetterchris]

That's a big difference in size to me.

[ps_bond]

Ditto. If you're offering 3.75mm (i.e. 2 decimal places) then I'd expect maybe +/- 0.5mm, depending on supplier.

[Wallace]

if you have checked it from a few rotations and that is the result, then I would certainly.

I quibbled for some emeralds that turned up at 1.89 when I wanted 2mm to match some diamonds. I was told they were calibrated and sent as 2mm. Having disagreed and subsequent ones sent, I noticed they then put a +/- with a new send out. I did get my 2mm in the end. I was sent over 40 out, including some over 2mm. But, I wanted what matched the stones in size that I already had. Not smaller or larger.

Clearly you are asking for a stone size for a specific reason and have paid for a 2mm. If there is no plus or minus at point of sale, then you need to have what you paid for.

When dealing with precious stones, they are charged at the slightest increment, so if it were me, as mentioned, I would certainly go back and ask for an exchange. It is a busy time, so someone may have been working on best interest to get them to you? (season of good will and all that!?)

[Tabby66]

Too much of a difference for me!!
Are you being charged a fixed price per stone or being charged per carat, you should only be paying for what you get!!

[trialuser]

Ditto. If you're offering 3.75mm (i.e. 2 decimal places) then I'd expect maybe +/- 0.5mm, depending on supplier.

Is that a typo?

[ps_bond]

Aargh... Yes. 0.05.