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| Montana Crucibles is a small private jewelry design studio owned by Don Doig of Manhattan, Montana, USA. Elias Alias is Don Doig's design consultant. |
Montana Crucibles jewelry is designed in wax carvings by hand and then cast into sterling silver or karat gold on premises. The wax technique employed is that developed in the 1970s by Elias Alias. From the cutting of the stone to the completion of the designed jewel, each piece is a one-of-a-kind hand-made creation. The gems are cut and polished individually by hand using diamond saws, wheels and belts. Don Doig does not cut stones in calibrated standard measurements, preferring to cut each piece of opalized wood in the optimum shape and size per each individual stone. Castings are made individually. |
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Please note the G.I.A. certificate on this page. That certificate indicates “Natural Opal”. Opal comes in a number of variations, and in south-west Montana a particularly unique form of opal presents geologic factors of interest. Plasma tubes are preserved microscopically and are visible as “tree rings” in the polished gems. Other features of this mineral include the wide range of striking colors, the combination of colors in unusual arrangements, and a quasi-translucency.
This is opalized wood. In other words, our mineral is like petrified wood which has been replaced with opal, in various colors. Opal is silica hydroxide. Gem quality opalized wood is uncommon. Our gems come from Montana, in the volcanically active Yellowstone country.
Not a lot is known about this deposit, but the sediments in the area are Tertiary, which would place it between 65 million and 2.5 million years old. We think that our form of opal was associated with a volcanic event, such as a pyroclastic flow, including, we think, a hot ionized plasma cloud, in the presence of water and sand.
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Perhaps a pyroclastic flow hit a forest which was growing in a swamp and blew it over and encased it in hot highsilica mud. Or, perhaps the flow melted snow and hot silica mud flowed down onto the forest. We plan to provide some of this material to a University in hopes of learning more.
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At any rate, because of the silica and water, and chemical and physical influences of a very hot plasma cloud , a great deal of the fine wood
structure was preserved and is visible in our colorful gems. The microscopic wood detail is remarkable, and detail is visible in our gems which is not visible in fresh or dried wood, or agatized petrified wood.
It is interesting to view these pieces under a strong light with good magnification. In most specimens you can see the plasma tubes inside the
growth rings.
Although we have chemically stabilized all of our Montana Opalwood gemstones to enhance durability, these gems, as with any opal material, are fairly fragile and should be worn with proper care.
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