O.K. I'm a book addict. If there is a book on my areas of interest, chances are, I've got it or will have. Not just the latest book on whatever, but older books also.
I was reminded of how useful older books are when I recently received the latest offerings from Rocks of Ages (http://www.rxofages.com/). In their listings they have many books that are very hard to find. One in particular is "A System of Mineralogy" by J.D.Dana. This was originally printed in the mid to early 1800's (I know the 2nd edition was in 1844) Any edition up until the 7th edition (1944/52&62) in all three volumes are great. On the 8th edition it all went wrong. It was edited badly, condensed and poorly laid out. Faith was lost in these well respected tomes.
Never underestimate the value of older books. If you want to go gold prospecting, rock hounding or gem testing on a budget. Get an old book! Gold prospecting is big business today, but in a book of 50 -100 years ago, different types of technology were used which are now fairly easy to re-create in a small home workshop. Some old books on gem testing were published before all the flashy equipment was available. They would give instruction on making equipment. I still use a round flask full of copper sulphate solution on occasion as a blue light condenser. I picked this up from a 50's book.
Although they can be very useful, don't forget to keep up to date. If you are gem testing, it's no good relying on out of date information on treatments and synthetics. Just a quick one this time.
Take Care,
Damian
Tuesday, 29 June 2010
Thursday, 10 June 2010
Diamond Certification.
Recently a customer asked a colleague for a D colour, Flawless (a term I think should be revised if all the gem labs are trying to say inclusions or clarity characteristics are not flaws), brilliant cut diamond ring in a Platinum mount. We didn't have anything, but to get the conversation going, she took out a D, VS1 (very slightly included) in Platinum. The customer looked shocked to see our "lesser quality" stone was about the same price as the D, Flawless he had seen in a previous shop.
She was confused and so was I. When I sat down and worked out from trade price lists, how much the stone should cost. We couldn't even buy the stone for a trade price for that, let alone in a Platinum mount! Something must have been wrong.
The customer was a reasonable person and I asked if they could go back and check that there hadn't been a mistake. When he came back, he had details of measurements, certificate etc. The main difference was the Lab issuing the certificate. Ours was a GIA (Gemomlogical Institute of America) and theirs was an EGL (European Gemmological Laboratory).
In the past I have been asked to compare certificates to diamonds in order to ascertain they are the same stone. Some labs have been easier to match than others. GIA and HRD (Diamond High Council of Antwerp) certificates are usually easy to match as I agree with the grading. With other labs I have found it quite difficult as the stones and certificates are very different, sometimes easily being 2 grades out ( a major difference in price). I've been grading for many years before anyone makes a comment on my abilities compared to a lab, and as a buyer I have to be right or the profits suffer.
After speaking to many brokers, suppliers and industry professionals, I have found out there is a definite hierarchy in labs and their certificates. The reasons for this are many and varied. From the amount of labs under one banner in different locations making consistency difficult to commercial reasons, if a lab grades your diamond higher, you may make more money on it, so they become popular.
The obvious front runners are GIA and HRD. They are both not-for-profit organisations, meaning they plough any left over funds into research, education and generally being better. The AGS (American Gem Society) is thought of highly in the states due to a small tightly controlled team providing consistent results. Anyone else it seems is fair game although IGI (International Gemmological Institute) seems to lead the runners up, even though they issue certificates on mounted stones often, which I don't like.
The other certification to watch out for is when a shop does their own. There is a certain high street chain in the UK that states that their Managing Director grades all their diamonds. If he was doing this for 12 shops, let alone how many they have, he wouldn't have time to manage and direct! As always, Buyer Beware, but trust is key.
Many lesser labs mean heavy discounts on the normal trade prices explaining the difference in price. If the above stone was a F, VVS1 the price would be bang on. Think about it.
Take care,
Damian
She was confused and so was I. When I sat down and worked out from trade price lists, how much the stone should cost. We couldn't even buy the stone for a trade price for that, let alone in a Platinum mount! Something must have been wrong.
The customer was a reasonable person and I asked if they could go back and check that there hadn't been a mistake. When he came back, he had details of measurements, certificate etc. The main difference was the Lab issuing the certificate. Ours was a GIA (Gemomlogical Institute of America) and theirs was an EGL (European Gemmological Laboratory).
In the past I have been asked to compare certificates to diamonds in order to ascertain they are the same stone. Some labs have been easier to match than others. GIA and HRD (Diamond High Council of Antwerp) certificates are usually easy to match as I agree with the grading. With other labs I have found it quite difficult as the stones and certificates are very different, sometimes easily being 2 grades out ( a major difference in price). I've been grading for many years before anyone makes a comment on my abilities compared to a lab, and as a buyer I have to be right or the profits suffer.
After speaking to many brokers, suppliers and industry professionals, I have found out there is a definite hierarchy in labs and their certificates. The reasons for this are many and varied. From the amount of labs under one banner in different locations making consistency difficult to commercial reasons, if a lab grades your diamond higher, you may make more money on it, so they become popular.
The obvious front runners are GIA and HRD. They are both not-for-profit organisations, meaning they plough any left over funds into research, education and generally being better. The AGS (American Gem Society) is thought of highly in the states due to a small tightly controlled team providing consistent results. Anyone else it seems is fair game although IGI (International Gemmological Institute) seems to lead the runners up, even though they issue certificates on mounted stones often, which I don't like.
The other certification to watch out for is when a shop does their own. There is a certain high street chain in the UK that states that their Managing Director grades all their diamonds. If he was doing this for 12 shops, let alone how many they have, he wouldn't have time to manage and direct! As always, Buyer Beware, but trust is key.
Many lesser labs mean heavy discounts on the normal trade prices explaining the difference in price. If the above stone was a F, VVS1 the price would be bang on. Think about it.
Take care,
Damian
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