Just bought a loupe! Novice needs advice...

[dc20063]

I just purchased a 10x and a 30x loupe and am looking for advice on using it to purchase diamond jewelry on the secondhand market. I took a trip to a nearby city and while perusing a pawnshop, I found some diamond jewelry (rings, pendants) at great prices!

Under their jewelry lighting, every piece sparkles like crazy, and although I know most are probably low-quality stones, there might be some true treasures there, too!

Most of the diamonds are small diamonds (under 1 ct), what should I look for with my loupe in small diamonds that are already set?

 

[denverappraiser]

A loupe can be a useful tool for clarity grading and checking condition as well as reading hallmarks and girdle inscriptions.

Pawnshops vary wildly in their skills but EVERY stone in there has been looked at by the pawnbroker before they put it out and they formed an opinion on what it was and what they could get for it. It's worth noting that what they charge has nothing whatever to do with what it cost them. Those are two different transactions. That means that you are fundamentally having a battle of wits with the owner of the pawnshop over who his the best grader. He/she has a loupe too by the way. There are definitely people who succeed at this and you have a couple of advantages but then so do they. The game is not against the salesperson in front of you, it's with the store owner.

I see this process quite a bit from both sides. I have customers who buy things from pawnshops and pawn dealers who want to know what they have so they can price things properly. When I see errors, it usually comes from incorrect measurement (especially depth) and therefore incorrect size calculations, misgrading color, and misidentifying gemstones other than diamonds.

 

[dc20063]

A loupe can be a useful tool for clarity grading and checking condition as well as reading hallmarks and girdle inscriptions.

Pawnshops vary wildly in their skills but EVERY stone in there has been looked at by the pawnbroker before they put it out and they formed an opinion on what it was and what they could get for it. It's worth noting that what they charge has nothing whatever to do with what it cost them. Those are two different transactions. That means that you are fundamentally having a battle of wits with the owner of the pawnshop over who his the best grader. He/she has a loupe too by the way. There are definitely people who succeed at this and you have a couple of advantages but then so do they. The game is not against the salesperson in front of you, it's with the store owner.

I see this process quite a bit from both sides. I have customers who buy things from pawnshops and pawn dealers who want to know what they have so they can price things properly. When I see errors, it usually comes from incorrect measurement (especially depth) and therefore incorrect size calculations, misgrading color, and misidentifying gemstones other than diamonds.

Is there a way to tell a simulated stone from a natural diamond with my loupe?

 

[denverappraiser]

A loupe can be a useful tool for clarity grading and checking condition as well as reading hallmarks and girdle inscriptions.

Pawnshops vary wildly in their skills but EVERY stone in there has been looked at by the pawnbroker before they put it out and they formed an opinion on what it was and what they could get for it. It's worth noting that what they charge has nothing whatever to do with what it cost them. Those are two different transactions. That means that you are fundamentally having a battle of wits with the owner of the pawnshop over who his the best grader. He/she has a loupe too by the way. There are definitely people who succeed at this and you have a couple of advantages but then so do they. The game is not against the salesperson in front of you, it's with the store owner.

I see this process quite a bit from both sides. I have customers who buy things from pawnshops and pawn dealers who want to know what they have so they can price things properly. When I see errors, it usually comes from incorrect measurement (especially depth) and therefore incorrect size calculations, misgrading color, and misidentifying gemstones other than diamonds.

Is there a way to tell a simulated stone from a natural diamond with my loupe?

It takes a bit of practice but yes.

Glass almost always has wear problems, usually has spherical bubbles and chipping on the girdle.
CZ girdles look different and they usually have wear on the facet junctions. They're internally super clean, which is a red flag.
Moissanite is doubly refractive. Easy peasy if you practice what to look for.
Naturals on the girdle with a trigon appearance are a shoe in for diamond. Certain internal inclusions also only appear in diamonds.
Other natural inclusions rule out the synthetics. Other white stones, like sapphire or topaz, can be separated by the same sort of ways mentioned above.
Separating exactly which non-diamond you're talking about is tough and usually takes more equipment. Separating white sapphire from synthetic white sapphire can be difficult for example.
That said, if we're talking about pawn shops, every one I've ever been in has a handy thermal conductivity tester to demonstrate that diamonds are diamonds and it's usually part of the sales presentation, especially if you ask.