Vibrant Color Enhancement: Heat treatment is the key to transforming the color of rubies and sapphires. This process can strip away unwanted brown or orange tones, bringing out the gems' natural, vivid blue, red, or other captivating colors.
Superior Clarity: By reducing or even eliminating internal inclusions and flaws, heat treatment significantly boosts the clarity and transparency of rubies and sapphires. The result is a cleaner, more brilliant gem that sparkles with enhanced beauty.
Enhanced Durability: Heat-treated rubies and sapphires gain increased stability and durability, making them more resistant to daily wear and tear. This ensures their beauty remains intact over time, even with regular use.
Greater Availability: The process of heat treatment expands the market by improving the color and clarity of these gemstones, making a broader range of high-quality rubies and sapphires accessible to consumers and jewelry designers alike.
Uniform Appearance: Heat treatment can remove "color zoning," or uneven color distribution, within rubies and sapphires. This results in a more consistent and visually appealing gemstone.

In my line of work, you learn there are two ways to heat corundum: the old way and the new way.

The Old Way: Back in the day, it was all about finesse. Jewelers used simple blowpipes, relying on skill and experience to get the job done. Think artistry over exact science.
The New Way: Now, we've got electric muffle furnaces with precise temperature controls. No more guesswork – it's all about control and consistency.
Temperature Matters: The heat plays a big role, and it can range from 700 to 1800°C, depending on what you're trying to achieve. Lower temperatures (around 700-1000°C) give you subtle color tweaks without messing with the gem's insides too much.

In summary, heat treating rubies and sapphires brings out their best by enhancing color, clarity, and durability, and increasing their availability. This process ensures these precious gems are as stunning and desirable as possible.