Several mines are open to the public.Įxploring a pit mine can be a dangerous occupation. Gem-grade sapphires and rubies are also found in and around Franklin, North Carolina. In the United States, the state of Montana has produced sapphires from the Yogo Gulch deposit near Helena. Pakistan, Afghanistan, India, Tanzania, and Kenya also produce sapphires. Australia leads the world in sapphire production, specifically from basalt-derived placer deposits in Queensland and New South Wales. Historically, most sapphires have been mined in Sri Lanka, Madagascar, and Myanmar.

For instance, in the Mogok region of Myanmar (Burma), the mines are located in the alluvial valleys of rivers. In addition, through the weathering of gem-bearing sedimentary rocks, these minerals are found in the form of 'placer deposits' at streams and rivers. Sapphires (as well as rubies) can be found in various rocks, mainly those of igneous or metamorphic origin (Sethi 1997). In addition, wars have been fought and thefts have been committed in attempts to acquire these precious stones. Yet it needs to be remembered that these gemstones (among others) were recovered by the hard labor of miners working under difficult circumstances at the risk of their lives.

Sapphires are part of the crown jewels of royalty and are a mark of wealth and luxury. For instance, synthetic sapphire wafers are used as the faces of high-quality watches and as the substrates for semiconductor devices based on gallium nitride. Synthetically produced sapphires are used for various applications. The red variety (produced by the presence of chromium) is known as ruby. The term sapphire is commonly used in referring to the blue variety, but nearly all the colorful gem-quality forms (except red) are classified as sapphires.

Pure corundum is composed of aluminum oxide (Al 2O 3) and is colorless, but trace amounts of various elements (such as ] or nickel) produce a range of colors, such as blue, green, yellow, orange, pink, purple, and red. Blue, pink, yellow, green, white, and parti-colourĪ sapphire (from the Latin sapphirus and Greek sappheiros, perhaps derived from the Hebrew word ספּיר, sapir) is a gemstone belonging to a family of gems that are varieties of the mineral corundum.

White sapphire hardness