Types of Sapphires
Sapphire is one of the four precious stones. The name of these stones, ‘sapphire’ may derived from the Greek Sanskrit 'sanipriya', which means "dear to the planet Saturn.".
The color of sapphire is blue in general. Sapphires that are red is widely known as rubies. Pinkish-orange sapphire stone is referred as the padparadscha (which means ‘lotus blossom’, derived from Sinhalese language) and it is commonly used for decorations, and some people consider it as a “feminine sapphire” since they are used for girly jewelries. Other sapphires colored differently than the color red, pinkish-orange and blue are called fancy sapphires. Green and yellow sapphires have traces of iron which gives them their color. Sapphires that are pink in color have trace element of chromium, if the pink color is deeper then the higher its value as long as the color of the stone is going toward red of rubies. Some of sapphire stones are not well saturated and show tones of gray.
The most expensive types of sapphires are the blue sapphires, which is also the most common one. The finest blue sapphires are the kind of blue that contain less than 15% of the purple hue. Purple sapphires which contain the trace element vanadium are lower in price than blue sapphires. All sapphires are 90% heat treated to a temperature of 3000 °C to give a better blue. If you want to know whether the sapphire has been heat treated or not is to check and notice the rutile needles within the gems under magnification. An unheated sapphire has unbroken needles, and if the silk is gone or can’t be seen then the gem was heated adequately. If the silk is partially broken then the stones have gone through a process known as low tube heat, where the rough stones are heated to 1000 °C for about 10 – 20 minutes. This takes out any gray in the stone and improves color saturation.
Like rubies, sapphires are originally mined in Sri Lanka. The other best place to mine sapphires is Kashmir, a northwestern region in the sub-continental Indian. Sapphires can also be found in every cut and color at the undergrounds of Madagascar, China, Myanmar, Thailand and Australia. In fact, Madagascar tops the list of the finest sapphire productions. Sapphires are rated a hardness of 9, they are just below diamonds on hardness scale of Mohs, and do not cleave which makes sapphires perfect for faceted gemstones.
Sapphires are the birthstones for people who born in the month of September. You can see more complete list of birthstones here.