MINING FOR SAPPHIRES IN MONTANA
In June’s newsletter, we also did a story on mining for sapphires in Montana. One of the places we mentioned was “Gem Mountain” located in the Sapphire Mountain Range in the southwestern part of Montana near Philipsburg. It was established in the late 1890’s. Today, at this particular mine, the public is welcomed with open arms. You pay for a bucket of gravel (which they have retrieved, not you) and wash through it to see if you find any sapphire nuggets. They offer heating and cutting services to finish your gem for you. To see this setup, go to: http://www.gemmountainmt.com
Anyway, in mid-June we made a trip to Montana to check out Gem Mountain. This was part of an informal trip that our Smithsonian gem collector’s group put together. There were about ten of us in the group and we all stayed at the same ranch (fun!).
While I have posted some pictures of our trip on Facebook, here are some that show Gem Mountain itself as well as sapphires we found. We found well over 400 carats of sapphires. However, much of it is what they call “fishbowl gravel” (that is, not worth anything!). Many were too small or too fractured to be of any value. The sapphires came in a variety of colors. We found “coke bottle” blue/green, some with blue streaks, a few pinks, and a few yellows.
Most people think “blue” when they think of sapphires. That is certainly true, but they do come in a rainbow of colors (see below). When a piece of sapphire comes out of the ground it doesn’t look too blue; in fact, it only looks slightly blue and that blue is often in streaks (through the stones). So, how do they get that deep blue color, then? Well, nearly 95% of sapphires that are for sale on the market have been “heated” to bring out the color. This heating (a couple times at temperatures over 1500 degrees F) gets the atoms in the stone moving around and creates color.
The first three pictures below were taken at the “Gem Mountain” facility. In the background of the first picture is a long blue rinsing center. One buys a bucket or jug of gravel, dumps some of it into a mesh screen box, rocks it back and forth in the water (makes the sapphires go to the bottom because they are heavier than the other stones), and then dump it over onto a table. The second photo shows the “dump” with coke bottle green stones on top of the square pile. These are the rough sapphires. The third picture shows folks picking through their “dumps”. As the perspective shows, these are small stones we are looking through and for. But, all in all, it was fun (if you are a rock-aholic).
After that are photos of the stones we found. Some of these we will send back to Gem Mountain to be heat treated (labeled “cuttable”). If they survive the heat treatment without breaking or cracking, then we will have them faceted. About 80% of the stone is lost in the faceting process. This loss is due to the shape of the sapphire rocks (being rounded). The actual shape of a sapphire crystal is a tapered 6-sided spindle and can produce a larger faceted stone (see below for a picture of natural, spindle-shaped sapphire crystal).
