ID mark on sterling ring, & other questions

I'm really trying to learn about jewelry, so any help you can offer is more than welcome.
This ring is marked 925, and there is another mark which looks like a "C" with a shape of maybe a diamond next to it. I tried searching for something similar with no luck. I thought perhaps it might mean the diamonds are CZ or something?
I just got a new diamond tester, and I've been playing around with it this morning, and I admit I really don't know what I'm doing, but the diamonds are testing as real, and also the blue stones are testing as diamond? What am I doing wrong?, I wouldn't have thought there would be real diamonds in a sterling setting..?
Thanks for your thoughts.

 

Sorry I can't help with most of your questions, but I can tell you that diamonds set in sterling are both common and popular these days. Most of the luxury fashion designers have been doing it for the past decade - yellow/rose gold is passe' in high fashion jewelry these days.

 

What type of diamond tester do you have? The heat dispersion type often has a row of lights on the side, these need to be set according to the size of the stone. Usually a poitive is very positive, if you have to 'force' it to beep, you probably do not have a diamond.

 

Thanks so much Mansons & Af
Here is a pic of the tester & a drawn image of that mark, because it's hard to get a good image of. (Pardon my terrible drawing, I'm a bad artist).
I tried the settings on the tester at 2, 3, 4, 5, &6, and got the same strong result with all of them.?? I also tried a bunch of other jewelry with stones and diamonds, or faux diamonds, and they all seem to give the correct result., but I need to keep trying more jewelry to learn how to do this correctly.

 

I have a tester just like that, and find it robust and reliable.

 

Thanks again Af. I've been playing around with it more, and it does indeed seem to be very reliable with the tests I'm doing. What I don't understand is why it's testing for diamond on the blue stones? I've also been testing a bunch of other gemstones, and it does not give positive for diamond on any of them......but I do not have any other blue stones for testing to see how this reacts to other blue stones.

 

Diamonds are sometimes blue.

Since it is a fairly modern ring the stones could be synthetic. Very small diamonds can be pretty cheap wholesale to the jewellery trade.

 

Thanks Af, you're a great help, and I appreciate it.

 

I would have thought sapphires ????

 

Heat dispersion in sapphires differs from diamonds because the elements involved are different. The pure carbon of diamond has different properties from the aluminium oxide (corundum) that is sapphire. That's how testers of the type shown above distinguish between the diamond and other stones

 

Ijust wondered if the diamond tester was calibrated??? BWDIK??? Sapphire is my birthstone and thats why I thought sapphires

 

Thanks all.
I just went to my "go to" gal, down at the gold buying jewelry store. She' really nice, and I sell gold to her every now and then, and I brought her some today, in hopes she would tell me her thoughts on this ring. She's pretty confident that they are moissanite. But she didn't use her tester, she just looked through her loop.
So, yes Af, synthetic they are. Thanks again

 

Moissonite aint cheap. It generally sells better than diamond. Make sure you aren't touching the metal prongs when testing. On these testers, sapphire will go about 90% as high as diamond.

 

"Due in part to the similar thermal conductivity between moissanite and diamond, it is a popular target for scams; however, an electrical conductivity test (with a check for birefringence) should alert any buyer to fraud" (from Wikipedia)

That's what fooled the diamond tester, since it works by thermal conductivity. Your experienced tester spotted the double refraction or birefringence.

 

Make sure you aren't touching the metal prongs when testing.

That model make a rapid bleeping noise if you touch the metal, it's very distinctive.

The tester is very good for the older pieces of jewellery.

 

Thanks much Af & Terry.
No, I'm not touching the metal...well I did a few times on some of the things I tested, but quickly realized the mistake.
Yes Af, she said there was no need to use the tester, after she looked through her loop. She said they are moissanite.
So now my next question...if I want to list the ring, how do I guarantee it's moissanite to a potential buyer? Would I have to have a jewelers appraisal? In which case would probably cost more than the rings worth., Or buy a moissanite tester? What would you do?

 

I'd list it according to the best of my knowledge and belief. In this case the evidence seems adequate to me. An air of quite confidence carries more weight than loads of explanations.

 

Take it to a jeweler.

 

Thank you Af & Marko.
You all are a great help.