What do you mean by Heat Treatment?

One of the most common treatments for gems is heat treatment. But in the absence of heat treatment of gems, the superb quality gems are difficult to obtain. With the availability of gem prices and it is available only exclusively for the rich. That being the sole reason the untreated gems have about 30% to 50% higher prices. Rubies, sapphires, tanzanite, citrine, aquamarine, tourmaline, blue topaz, and all other gems need to undergo heat treatment. The time and temperature required to bring about a change can vary from 400-degree Fahrenheit to 1300 degree which brings about a change in the color.

Why is heat treatment used in the first place?

One of the biggest reasons for using heat treatment is to bring about a change in the tone of the gem as mentioned above but it also offers better clarity. Sapphire and rubies may need a greater temperature for enhancing the color tone and making the clarity better. Heating can either be used to darken or lighten the color. Heating and amethyst can offer color from deep purple to orange-hued citrine. Tanzanite can be explained as a trichroic gem with a blue tint, along with yellow and violet color. Without treating it with heat the color may look like a diesel gem or one can say it is a brownish blue-red tone. As and when the gem is heated the color changes and what is obtained is known as tanzanite. This makes the yellow color gone forever.

Bottom Line

What's the correct one can't say? As heated tanzanite is still Tricor and the 2 colors such as violet and blue are visible. Heating a ruby can change the color and enhance the clarity as most of the Burmese rubies originating from Mong Shu are known to have a blue core. As heating, it changes the blue to superb red gem.