September 2008

I am honored and excited to be the new editor for Metal Clay Connections. I would like to thank Linda Bernstein for starting this newsletter and doing such a fantastic job. I will do my best to maintain the high standards Linda has set. In order to make this online newsletter a success, I need your submissions! Anything you have, even if it is just a comment or a correction is appreciated. If you have ideas on topics you would like to cover, please let me know.

In this issue, we focus on Gemstones and Metal Clay, a subject I have been facinated with for some years now. Color, sparkle, iridescence, luster, pattern, rarity, and beauty top the reasons people choose to add gems to their jewelry creations. But how do we define what is and is not a “gem?” In its broadest sense, gems can include pearls, coral, shell, amber, as well as inorganic minerals (gemstones). More rigid definitions confine the term to gemstones—crystalline minerals that can be faceted, are durable, and rare.Gemstones can be natural, synthetic, or enhanced to improve color or clarity. One good place to learn more about the subject of gemstones is Professor Jill Banfield’s online course Gems and Gem Materials. The Gemological Institute of America also has online materials on the subject.

Whatever your personal definition, a vast array of gems and gemstones are available for metal clay artists to include in their work. Some can be fired in place, while others need to be set after the metal clay has been fully sintered. Information on stones that can and cannot be fired include Kevin Whitmore’s gem tests and my own list of natural stones and list of synthetic stones that can be fired in place or are best set after firing.

Countless techniques are available for setting gems, gemstones, and other objects. Virtually all the metal clay books include at least one or two methods for setting gems. Specialized resources for learning about setting stones in metal clay include:

Margaret Schindel’s Squidoo lens Setting Gemstones in Metal Clay.

My own booklet Using Investment Models for Setting Stones in Silver Clay

Lorrene Davis’ booklet Setting Gemstones in Metal Clay

We can, of course, only scratch the surface of the topic here, but I hope you will find the articles, projects, tips, and links helpful and informative whether you are a novice or an experienced metal clay artist.


Mary Ellin D’Agostino

Mary Ellin D’Agostino

Master jeweler Hugh Power has been in the jewelry and lapidary business for 43 years. Recently retired from teaching the Jewelry, Stonesetting, & Lapidary class at the Richmond Art Center in Richmond, CA, Mr. Power found time to talk to me about gemstones and what the silver clay artist needs to know about selecting and purchasing gemstones.

Q: You have been involved in all stages and aspects of the lapidary enterprise from finding the gems in or on the ground to cutting and setting them. Could you tell us a little about each of the stages?

A: Well, normally you start out cutting cabochons first, then migrate to faceting, then you have to make mountings for faceted stones. Learn from someone who is experienced; working with an experienced person will help you learn quickly

Q: You have been involved in buying and selling stones and have traveled extensively. What can you say to the novice about buying stones? What kinds of things should they be aware of and look for?

A: That’s something you learn from experience. You have to be careful because some sellers may try to sell you blue topaz as blue sapphire and one of the first things you need to know before you start buying gemstones is to learn to identify them. Identification is most important.

Q: What makes a stone a gem or a dud? How do you define “gem?”

A: Mostly there are two factors to worry about. One is durability. If it is going to be worn in a ring, it has to be sapphire or harder because the other stones will wear away very quickly. And the reason it’s a gemstone is because it is rare and because it is a pretty color. It was cut properly, it has a brilliant sparkle, and it attracts attention. That is what we wear jewelry for: to catch somebody’s eye. Otherwise, why bother?

Q: So people should learn about the stones before they go out to buy them?

A: The best thing is to get somebody that is already experienced because the general rule is that dealers will keep the best and sell the rest. Always. So you don’t get a chance to see the good stuff unless you know somebody. They will try to sell you reject quality stones that have very little value.

Q: What about the beginner who is just learning to make silver clay jewelry or fabrication who just wants a spot of color?

A: They need to buy stones from a reputable person, one who will guarantee that the stones won’t disintegrate in the clay and will maintain their color. It is very important because you don’t know the difference. A beginner won’t know the difference between a red garnet and a ruby, or if it is a red spinel. One nice thing is that sapphire comes in all colors. You can get sapphires that are yellow, sapphires that are green; you can get them in purple, and all colors.

Q: Are these the safest stones then?

A: Sapphires are the only ones to really work with [when firing in silver clay].

Q: What about lab grown stones?

A: Synthetic. Again, a beginner has to be careful because it is very common for some unethical dealers to salt a package with a few synthetic stones amongst the real ones.

Q: And how would you tell that? Would a jeweler’s loop be enough or does it take a microscope?

A: It takes a microscope to look for the growth rings of the sapphire boules. However, unlike synthetics made by the flame-fusion method, flux grown gems have no growth rings. For example, Kasham (synthetic) rubies were shipped to Burma, where they are then tumbled in the streams, and later sold as natural gemstones. The Kasham rubies are beautiful stones. They are flux grown so there are no growth rings. It is really the buyer be ware. A lot of times, if a deal seems too good to be true, there is something wrong. They are going to sell them some way or another.

Q: Are there are a lot of online websites collecting parcels and reselling them without checking or guaranteeing the stones?

A: When you think about it, most of those places don’t care. They have to sell everything they buy and when we were in Bombay (Mumbai), we went to the International Gem Corporation. We took them a phone because their phones were so bad and they were so happy about it, they took us into a back room and said: “You can look through this 5 gallon bucket of rubies and take a handful.”And we thought: “Oh boy, we are going to get a handful of rubies!”

My brother-in-law and I sat down on the floor and went through every one of them and I think we found two of a quality that you could cut. As we got through with them, we put them back in the bucket and a lady would come in and would scoop, wipe the scoop flush, bag the stones and went off to ship them. Stones have usually been high-graded, and high-graded, and high-graded until by the time you get to see them there may be nothing of any value there.

That’s why in Jaipur, India we go to Alok and Nirmal Chordia, because they will give us first choice on a lot of this stuff, direct from the cutters. The quality is always better. The best solution is a good connection, like Alok, who sells you something that is exactly what he says it is and if there is any problem you can get your money back. It is that simple.

Q: If someone is buying faceted stones or cabochons, is it better for them to buy something more expensive or stick within their budget and buy lesser quality?

A: If it is going to be a gemstone, it has got to be of good quality. It isn’t worth the time to make a beautiful work of jewelry and put a reject stone in it. The stone should be the best part of the whole piece of jewelry, the most expensive part.

Q: Can people find good deals at gem shows?

A: The gems at shows have been picked, and picked, and picked. At the show before you, people picked all the best ones. And the one before that they picked all the best ones. It isn’t until the dealer gets a new shipment that you might get some good stones, but the dealers might also be buying stones that have been rejected and rejected. The only really good source is a dealer like Alok because he hires the cutters. He grades the stones in three different groups: good, better, and best. If they are not good, it is junk and he sells it right after it is cut for anything he can get out of it. You can tell the rejected parcels because the papers are dirty. They have been opened, and opened, and re-opened; those parcels are just a waste of time.

When you were in Jaipur [Mr. Power took a number of students, including myself, to Jaipur India on a buying trip in February of 2004], you took the best stones that were passed around the table. Correct? Those were from the cutters. When Alok comes to the US, he brings his inventory that people like you and I have already picked through in Jaipur. All the parcels that come here have already been picked through. The dealers also have their own private stock of the stones which is their estate. The really good stones go in the back of the safe and nobody sees them, except someone who actually goes over there.

Q: So establishing a relationship with reputable first tier-dealers is important?

A: Absolutely. I had one customer who wanted a yellow sapphire for a ring that was for Astrological purposes. I got a sapphire that was absolutely perfect; we looked at it through a microscope. It was a beautiful deep yellow color and weighed 5 carats. Alok said he hadn’t ever put it out to show anybody, but he brought it out for me because I asked him for it. But we paid $140 per carat for it. The customer was willing to pay $2000-$3000 for a stone to wear on her finger for astrological purposes.

In reality, there is more fraud in gemstones than there is counterfeiting and other types of fraud.

Q: Intentional or unintentional?

A: As the old saying goes: Only your beautician knows. Only the cutter knows, because they’ve got the crystals. That is how Alok deals with the cutters, he has them all sitting around a room with one person who watches the cutters. There is another person who does nothing but keep track of the stones, the rough. He hands out one stone out to each cutter and keeps track until they bring it back again. That way there is no possibility of the stones being switched. The stones are on a dop stick and there is no way that they can get away with transferring a synthetic into their pile. Sometimes, when they have very valuable parcels, they strip search the cutters before they leave to be sure they don’t smuggle anything out of the cutting house.

Q: How can you tell the difference between a natural and a “lab grown” stone?

A: These are the same chemical composition as a natural stone. In order to tell them apart you need a lab analysis using a spectrograph to examine the light frequency emitted by the stone. If a synthetic is grown in a boule, you can see the growth rings with a microscope. The main thing is for people to know that there are ways they can check a stone. Check with a knowledgeable person to be sure your stone is genuine.

You can buy an expensive emerald it could be nothing but clear beryl on the top and bottom held together with green glue. You can test that stone with a refractometer and the stone will check as if it was a genuine emerald. Place the stone in an immersion liquid, and you can see that the top and bottom are clear. If someone has melted glass into the top of a ruby, for example, to fill a hole in it, you can’t see it with the naked eye, but you can see it if you put in a liquid (anise oil); all the internal flaws become visible.

Another thing to check when buying stones is to put them on a white surface with the table of the stone down, turn them around with your tweezers and look at them to look for any flaws or cracks in them. Then turn them over with your tweezers under a light. If they show a perfect shadow, they are well cut. If you see any light through the stone, it is rejected because it is not well cut.

Q: Is that because a well cut stone is a true prism?

A: Correct. All the light going into or entering the stone should be reflected back out again. You also need to check that the girdle edge is uniform all the way around and is not sharp. A sharp girdle edge is prone to chipping, and that will ruin a stone.

You should heat test all sapphires before using them in your jewelry. Before heating a stone, it should be completely clean and checked by preheating it with a soft flame. No sudden thermal changes or the stone might crack. When heating a stone, be sure it is on a clean surface—don’t use a soldering block that has flux or solder on it.

The best thing, if you are buying an expensive stone, is to become affiliated with someone who is knowledgeable and can give you a second opinion. You need books and good friends.

If you are buying smaller stones, millies, that are 3mm and under, you don’t have to be too concerned that they are genuine because these are cut from the off-cuts from big stones. 3-5 mm stones are affordable. When you go to 6 mm, the stones are about 1 carat in size, are scarcer, and these stones should be checked carefully for defects.

Q: Unless it is an off-cut from something that was treated before cutting?

A: Well, only your beautician knows. It is true, you can’t tell, after it leaves the cutters, where it has been.

Q: What about internet sources?

A: Anyone can put anything on the internet. There are several good gemstone reference books, but you need to check who the author is. That is a whole subject in itself. The best thing for people to do is to pick one thing to focus on and become good at it.

Thank you Hugh! You have been extremely generous over the years in educating many of us in the creation of fine jewelry. I really appreciate you taking the time to do this interview and share some of your knowledge with metal clay artists.
– Mary Ellin

Hugh Power can be reached by email at or through his website