Sapphire Mining
The date, 1894, the place, Gem Peak area on Rock Creek near Philipsburg, Montana. The first load of sapphires is shipped from Placer mines and eventually as far away as Switzerland for watch jewels and fine instrument bearings. Here was a world-class discovery and supply to meet a growing demand for corundum; sapphires and rubies.
Sapphires were first mined in the Rock Creek deposit about 1892. That Rock Creek deposit was known early on as being exceedingly abundant, and is notable as the only placer concentration plentiful enough to have been worked commercially for sapphires. Most sapphires are mined out of alluvial deposits, also called placer deposits, that have eroded from bedrock. There are only a few deposits that are actually mined out of the bedrock, the Yogo deposit near Utica, Montana being one of them. Since those early days, and continuing into modern times, Montanans and visitors have enjoyed mining gemstones for fine jewelry.
Rock Creek sapphires are found in gravel deposits in the Sapphire Mountains, but only in specific areas. They pay layer (sapphire bearing gravel) is below top soil and above bedrock, all of which vary in depth in any specific deposit. The top soil is the first removed and then subsequently returned in place after the pay layer is processed and returned to the site. Sapphire gravel is washed or screened to remove clay and large rocks. At this time in the process, the gem gravel is made available to you, the sapphire miner.
The sapphires removed were, and are, graded by color, clarity, structure, and size for uses ranging from display - of jewelry like the brooch displayed at the 1900 Paris Exposition "of over 200 stones, ranging from 1 3/4 to 3 carats each, every one of a different tint or shade", to rings, earrings, necklaces, and bracelets.
Of the four Montana sapphire regions, only Rock Creek has such a variety of distinctly crisp and sharp colors. As tastes have shifted to more brilliant gem jewelry, Rock Creek sapphires have come into their own. Particularly with the advent of readily available heat treating, Rock Creek sapphires are able to fill a niche worldwide. For more information see National Geographic magazine, October 1991, "Sapphires & Rubies". Colors range from the classic "cornflower blue" to "red-orange" and "mint green." The sapphires found and finished here have a character and beauty all their own.
A gem's specific qualities are discussed in terms of carats (size), color, clarity, and cut (shape and polish). The job of the cutter is to cut (polish) the raw gemstone to accent the colors and size inherent in the original stone. Chemically, sapphire and ruby are dialuminum trioxide (A1203), a clear and colorless mineral. Impurities present in the stones create the distinct colors. Iron makes yellow, iron + titanium is blue, and chromium makes red. Red sapphires are known to the world as rubies. An impurity common to most saphires is Titanium Oxide in the form of "silk needles" or "haze". This is the reason for the heat treating. Heat treating in the 1700 degree C to 2000 degree C range is necessary to dissolve the titanium crystals back into the surrounding material and "clear" the gem for maximum brilliance.
One of the most popular attractions of the Philipsburg area is the sapphire mining offered to the public. It is pretty unusual that people are able to dig through gravel in search of rare, fine gems, but that is what is offered in Philipsburg. Year round, sapphire mining is available at The Sapphire Gallery and Gem Mountain. Come and mine with us!
