Now for the fun part. Once we get all these materials to our studio (a.k.a. my house), what happens to them?


single-color sundrop The process is a bit different for single-color and multi-color sundrops. So I’ll start with the plain ones.

First step: Cut glass into strips. Very little waste in this step.
Second step: Melt glass into drops using the giant magnifying lens.


Me working at the lens I melt glass with a giant fresnel lens. 41×31 inches, it’s about 1270 square inches in area (0.82 square meters). Which means, at 1.4kW/square meter, about 1.1 kilowatts of energy are hitting the lens.

Melting glass with the Fresnel Lens
This is the fun part. First I tilt and aim the lens until the sunlight is focused on a rock attached to a wire stand. The lens rotates both horizontally and vertically, to adjust as the position and angle of the sun changes throughout the day. The rock moves up and down the wire stand for the same reason. With the rock as a backdrop, I can now see the bright spot where the sun is most intense (only with shade 8 welding goggles - it’s bright!)

Then I hold the end of the glass at the focal point (about the diameter of a fat pencil). The hot spot is pretty concentrated. As long as the piece of glass I’m holding is at least as long as a pencil, my hand is safe. And most of my body is actually in the shade of the lens.

The hot spot can get up to 3000 degrees Farenheit! But that depends on what I’m focusing on. Light has no inherent temperature - darker colored objects absorb more and will get hotter. Lighter colored things absorb less. Completely transparent glass - I can’t melt at all.


glass heating in the lens The end of the glass strip starts melting within seconds. I continue heating it until I’ve got a good molten glob, then flip the strip over so the glob is pointing down. Gravity and surface tension pull the molten glass into a lobe that cools as it falls and stretches into the Sundrop shape.


sundrop dripping

Timing is critical here - if I screw up, it falls all the way to the ground, becoming flat on the bottom. The final sundrop is connected to the strip by a thin stringer of glass, which I break off to disconnect it.


putting the ball on the end Later, I take the sharp-ended sundrop, and hold it in a pair of tongs, remelting the end. Surface tension forms it into a ball - which I’ll later use to hold the silver wire wrapping in place.

If you want to see this in action (and don’t live in Seattle’s University District), go to the Sundrop Jewelry web page and watch the movies!

Environmental Impact
Well, it’s all solar, so I’m not using up any fuel. The main impacts from this step are a small amount of glass waste (sometimes I screw up the Sundrops), and the impact from producing the lens. I’m not sure what kind of plastic is in the lens or how hard it is to make, but since the lens will last for several years before it’s too warped/scratched, I think it’s not too big of a deal.

Comparison to Lampwork
Lampwork (making glass beads in a torch) is the most similar type of glasswork to what we’re doing here. Since lampwork is often done on a small at-home scale, I couldn’t find really good numbers on energy use. But beads can often take up to an hour to produce (an individual lampworked bead is usually larger and more detailed than a Sundrop). There are two commonly used kinds of torch setups - single fuel (propylene or propane), and dual fuel (propane + oxygen). For single fuel, a 1lb propylene tank lasts for 3-4 hours - so only a handful of beads. Dual fuel will be more efficient. And since lampwork beads are larger and need to be annealed, there’s also energy used in a kiln heating step.


multi-color sundrop For single-color Sundrops, we have none of these fuel and energy costs - it’s all solar. For multi-color Sundrops, we do most of the heating in the lens - but there are some kiln and torch steps where we haven’t managed to go solar yet - more on the impact of those next week.

2 Comments »

This blog’s been empty for a bit. But now I’m back in town after a few weeks in Alaska testing out winter gear for an upcoming 4000 mile environmental expedition.

The last ingredient in a pair of Sundrop Earrings is rubber. We put little rubber ear nuts on the backs of the french ear wires. Partly to hold them on the card for display and shipping, and partly to prevent people from losing the earrings wearing them. Of course, people often don’t remember to use them, so we end up fairly often re-matching a mate to someone’s lost earring (something we’re generally happy to do).


Rubber tree
So, I have to figure out what these are made of, and where they come from. In the catalog, all it says is: “Rubber Hypoallergenic French Ear Wire Guards”. This could be either natural or synthetic rubber - it’s not specified. Wikipedia tells me that about 42% of rubber used is natural, and the rest is synthetic, so it could go either way.

Natural vs synthetic rubber. Natural rubber is a renewable resource, made from the sap of the Hevea brasiliensis tree. But rubber plantations can cause habitat loss when they displace existing tropical forests. Synthetic rubber is made from petroleum. Petroleum is obviously non-renewable, and synthetic rubber takes more energy to make (we’re using fossil fuels to synthesize polymers, while the trees use solar energy). I’m not sure how it shakes out in the end between these two, but synthetic rubber has been steadily replacing natural rubber.


Waste tires Unfortunately, trying to look up the impacts of rubber manufacturing on the web is leading me to a whole lot of dead ends, largely regarding tires. Apparently the disposal of used tires is a huge problem, and many many websites are eager to tell me about the various things that can be done with used tires, such as covering playgrounds, making asphalt, in flooring, rubber bands, etc…

What I’d actually like to know is more specifics about the rubber manufacturing in the first place. However, rubber ear nuts are only about 0.005 ounces/pair (a pair is about a tenth of an ounce total). In my calculations so far, I’ve been looking at 1000 pairs of earrings, almost 8 pounds worth. In all that, rubber ear nuts are still only about 5 ounces. Basically, I really doubt they’re a huge part of Sundrop Jewelry’s impact.

2 Comments »

About 15% of a pair of earrings is silver - in the form of ear hooks and wire. And this is the thing I’ve been most worried about in terms of environmental impact. Over the past couple years I’ve been very involved trying to fight a mining proposal in Alaska: Pebble Mine. This has led me to learn all sorts of frightening things about the mining industry’s track record and impact on the environment.

Mining Industry Record

• Mining is the most polluting industry in the country ( EPA Toxics Release Inventory).
• Major threats to water include acid mine drainage, cyanide spills, and heavy metal pollution.
• Fish are especially sensitive to heavy metals in the water (more than people).
• A recent study shows that 76% of the U.S. mines surveyed exceeded water quality standards, polluting rivers and groundwater.
• According to the Environmental Protection Agency (EPA), mine waste has contaminated more than 40 percent of the headwaters of western watersheds.

Buying Better Silver?
This begs the obvious question - can we avoid contributing to these problems by buying recycled or otherwise responsibly mined silver?

As far as I can tell - no. This is one of the big problems in the metal industry - there are so many middlemen, and no way for consumers to tell where the metal comes from. Hence no pressure on the mining companies to be more responsible. The numbers above are from the U.S. In third world countries, the problems are even worse.

Ethical Metalsmiths and No Dirty Gold have made some progress on demanding greener gold, and trying to pressure jewelry retailers to carry it. Gold is a bigger problem than silver, simply because gold is rarer and more precious. It is present at much lower concentrations in the ore, so more damage is done getting a given amount of gold out of the ground. But silver is subject to all the same problems - metal ores often occur together, so they actually come from many of the same mines.


Printing vs Paper and Glass Energy Use and Greenhouse Gases
This is a pretty rough calculation, involving a whole lot of metric/english unit conversions (courtesy of google). Searching for the ounces per ton of silver at different mines, and looking in the book “Golden Dreams, Poisoned Streams”, I found that 25 oz/ton seemed about right (number is on the high end to try and take into account that the ton of ore contains other metals as well). Then I headed over to Canada to get the
“energy intensity” of their mining industry, expressed in Gigajoules per metric tonne of ore. I’ll just assume Canada is representative. Then I multiplied that by how many ounces of silver you get in a ton of ore, and how many ounces are in a thousand pairs of sundrop earrings. I don’t have CO2 numbers directly, but am assuming the carbon emissions per energy unit are similar to glass and paper.

The answer is pretty rough, but shows that silver is several times more wasteful than paper or glass in straight energy terms. This is despite the fact that we use more glass and paper than we do silver. And it’s not even accounting for most of mining’s impacts described above - just the energy. I don’t have a great solution to. But it seems like what all users of silver need to do is start putting pressure on our suppliers - perhaps we can get a source of recycled silver.

A few more notes on Silver
In addition to silver being an environmental problem, it’s also been rapidly increasing in price over the past few years, along with most other precious metals. See Infomine, and the USGS summary and mineral yearbook. Demand for silver has been fairly flat - decreases in photography making up for the increases in other uses. One of the reasons is that there are now “Exchange Traded Funds” for silver and gold that make it easier for investors to buy and sell metals as a stock. This is important because it increases mining activity beyond the demand for using metals to actually produce things - increasing the environmental impact along with it.

No Comments »