Join us to learn about opals

Ians opalsCome learn about opals from Capricorn Gems’ Ian Bone. Understand  how opal is mined and see the process from rough to gems.

Thursday July 20th 6:30 PM

at our studio

22 East 49th street 4th floor NY NY

Free

All Welcome

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Latest update on our Met project

Hi all,

We received the analysis from the lab at the Met and now we need to verify the results against a piece that has proven to be authentic. The lab results themselves don’t prove anything, it is only that information in context that tells the story. Such as, an Etruscan piece that was excavated under scientific oversight or something with a verified provenance. We need to accomplish this  before we start on our actual reconstruction.

Untitled2

Untitled4The above photos are some of the pics I sent to their lab, to mark areas we wanted analyzed. We will compare our visual analysis  and the lab results to hopefully authenticate this piece.

Many of the museum staff are abroad over the Summer at various digs so examining other pieces at the moment will have to wait. In the meantime, we have moved forward with rock forging out an ingot to make some wire samples. The Etruscans didn’t have draw plates, so they made thin sheet, cut strips, wound them into coils, and rolled them between wood or stone to make short lengths of wire. I’ll show the process in detail once our gold sheet is ready and we have made some chisels to cut the sheet. Checking for artifacts of this process in Etruscan wire is an  important tool in verifying a piece. That is one of the things we will be looking for in our Etruscan discs.

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The Adventure Continues

2017-06-13 17.30.18

After getting to the point of everything ground and polished in the last post, I decided to patina. Getting a good patina requires good surface prep: no oils or fingerprints and a consistent, slightly matte finish. I would normally use pumice or a scotch brite wheel but I decided to try No Name (really, that’s it’s name) a metal prep sold for users of shakudo. You use it like pumice, a nice wet scrub over the whole piece to achieve a consistent finish.

2017-05-30 15.21.57

I decided to try Baldwin’s patina, made specifically for users of shakudo, etc. In chinese Wu Tong, you handle the piece for 3 days to form the patina. This metal will patina itself, a huge advantage considering any scratches will “heal” up on their own. I wanted to try the Baldwins, to see if it had advantages over the self patina.2017-05-30 15.29.09I used a Q tip and painted it on but I wasn’t able to get a consistent finish. I felt reasonably sure I had achieved an even finish with my prep so IF that was true (I’ll have to test that further) then it was my application method.2017-05-30 15.38.10

I consulted with my colleague Melissa Caraway (who does a lot more patination than I do)  and she said that dipping produces much more even finishes than brushing. I had only bought a small bottle of Baldwins, so I would need to get more to retry. So, I heated the bracelet to remove all of the patina and decided to try the self patina. I’ll get more Baldwins and try dipping on the next project. I just left the bracelet at our front  desk and we all handled it whenever we thought about it. Since it wasn’t getting continuous handling, I knew it would take longer than 3 days. It’s been a couple of weeks now. I should have taken a picture every day to show the continuum but I got distracted by other things.

The top picture is after one week and the bottom picture is after two weeks. I’m loving the patina so far but we will see what it looks like when it’s complete. Judging by it’s progress so far, I expect it will take a month or so more, but we will see. I love to experiment, there are tons of surprises. There are many sources online for exactly how to patina shakudo but to truly understand the process and be able to make choices that suit your design goals, you have to test, not just do what someone else did. That’s why we are always experimenting (besides that it is incredibly fun!), we want a deeper understanding of the why and how. Happy experimenting!

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Our Next Adventure in Hmty Km

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After grinding and sanding, my bracelet looks like this. I realized I didn’t engrave deeply enough in spots, so now that I’ve cleaned up, my lines look muddled from disappearing  or partially disappearing in places. I’ll remember that for the next time but for this experiment I’ve decided to go with the “abstract brushwork” look. You have to be willing to mess up as much as possible to learn. This is the most difficult lesson to teach. Students (naturally enough) want things to turn out well, so they hesitate to make mistakes. The only trouble is that holds them back from learning as much as they could, as quickly as they could. The best thing I ever did to accelerate my learning was to give myself permission to ruin pieces or at least make a mess. I learned exactly what a piece or technique looked like before complete meltdown or disaster and that helped me enormously in understanding the process. I certainly don’t want you to start destroying everything but maybe think about living a little more dangerously. It’s just jewelry….

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Inlaying Argentium Silver in my Hmty Km bracelet

After milling out my ingot and Melissa Caraway forging it to a lovely shape, my Hmty Km looks like this:6% Au 94% Cu ingot milled2

 

 

Since I love to experiment, I decided to add a bit of Argentium inlay to my Hmty Km bracelet. Patinas always look best with some contrast to make them pop and Argentium is so bright I thought it would be a great addition. I engraved some random swirls in the bracelet. By the way, we are running a Florentine Engraving Intensive this Summer, if you are interested in learning to engrave. I should have planned them out better but I admit I jumped the gun a bit and drew them on freehand. Always a mistake for someone who draws as poorly as I do….

Oh well. Here is a shot of the bracelet with an engraved swirl and one swirl with Argentium melted in it.2017-05-28 10.13.09

Since Hmty Km has a high melting point (in the 1900 degree F range) and Argentium has a significantly lower melting point (between 1410 and 1610 degrees F) it’s a safe proposition to just heat with a large torch and some liquid flux until the Argentium melts into the chanels. In Wu Tong, they use powdered silver for inlay but since I didn’t have any, I just used 26 gauge argentium wire and laid it out over the chanels.

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I worked my way around the bracelet and then went back to add more to any low areas. At the end, my bracelet looks like this:

2017-05-28 10.53.24Now, I just have to grind away the excess and polish to prepare for the patina.

Until next time…

 

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Hmty Km, the original black copper alloy

2017-05-02 14.51.03In working on our MMA reconstruction piece, I’ve been researching ancient bronze to better understand the composition of the tools we will be making. There is very little information out there on Etruscan era tools, and according to other who have studied this the tools were either melted down or corroded beyond recognition. I contacted two experts in ancient metallurgy from Academia.edu (a treasure trove of free information that I turn to often) and Dr Alessandra R G Giumlia-Mair has some helpful analysis she is willing to share. I find scientists to be incredibly helpful and willing to share information. It’s a great example to emulate in projects like this.

In reading some of her research papers, I came across the topic of Hmty Km (pronounced “hempty kem”) an Egyptian black copper alloy that is the predecessor of Shakudo in Japan, wu tong in China and was called Corinthian copper in the West. Apparently its use died out in the western world after it traveled to asia. This is the reason it is considered a Japanese technique today, its Egyptian and western beginnings being largely forgotten. It is primarily copper with small amounts of precious metals like gold and/or silver. Even percentages as small as 1 or 2 % gold greatly alter the patinas you can achieve. Of course, I was intrigued and had to whip some up right away. There are many, many recipes to choose from so I started with a few straightforward ones. An important element in many of the original alloys  is arsenical copper, or copper ore with arsenic in it, as it occurs in nature. Yikes! From my research so far, it seems the arsenic makes a harder alloy. Unless or until I can figure out a way to use the arsenic safely (which is doubtful) I will make do with a softer arsenic-free alloy. It remains unclear to me what effect, if any, the arsenic has on the patina of the finished piece but I might not be able to test that for safety reasons. It’s all fun and games in the studio until you give yourself arsenic poisoning….

The recipes I made are 94% Copper 6% Gold, 93% Copper 6% Gold 1% Silver and 70% Copper and 30% gold. We will see how they turn out when patinated but the shades are very lovely as is. Of course, if I wanted to keep them this shade they would have to be waxed or lacquered to seal in the color and keep them from oxidizing.6% Au 94% Cu alloy

left 6% right 30% AuLeft 94% Copper 6% gold, right 70% Copper 30% gold

 

 

 

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Construction details in Etruscan discs

Untitled-2Hi all,

Take a look at another one of the detail shots! From this view we can see two things clearly about their construction.

First, as indicated by the two arrows, you can easily see the seam between the thinner top layer and thicker back sheet.

Granulation works best on thin sheets (we usually use around 30 gauge) so we usually work on thin sheets and then solder them to a thicker

(sometimes lower karat) back sheet for strength; just as this ancient goldsmith has done.

Secondly, as indicated by the red rectangle, you can see the outer edge is not granulation but beaded wire. Beaded wire is an ancient technique

we haven’t practiced. It involves making relatively short lengths of wire (there will be more about how the ancient goldsmiths made wire in future posts)

and then using a tool to score horizontal indents along the length of the wire. This tool, along with the wire, was handmade and I feel like you can see how the same

toolmarks are repeated on each “bead”. You can also see how there is a typical looking fused connection between each bead and the backsheet.

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Check out the peg underneath one of the granulated discs

Untitled8aThis is a closeup of one of the concave granulated discs. At this level of magnification, you can easily see the peg it is resting on. This peg goes through the backsheet and is covered up by a small dome on the back. Also notice how easily you can see the seam in the wire circling the dome. Some slight damage to the back pushed this particular peg up a bit, making it a little higher and easier to see than the others. Although pristine ancient pieces are beautiful to look at, damage often reveals construction details that are difficult or impossible to see otherwise. Hurray for damage!

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The back of the earring from the MMA

14b14aHere is a back view of the disc earrings from the MMA. Seeing the backs of things is so instructive. For example, you can see that the concave granulated discs on the front are attached to the back with pegs then covered up with the small domes you see here. The center flower is attached the same way with the center dome. The backsheet of the center section is probably separate as well. For those of you who granulate, it’s easy to see the rational here. I use the same concept when making elaborately granulated pieces. It’s much easier and safer to granulate smaller parts and then assemble them using solder than to attempt a lot of granulation on one large piece.

The only evidence I see of any method of attachment for wearing these earrings is the two holes in the edges of the center circle. Presumably the ear wire was a separate piece. (?)

I’ll try to find another similar apparatus in some other  ancient examples.

Till next time!

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