Heat Treatment & Sapphires: What It Is & How It Works

With a variety of shapes, cuts, and colors to work with, sapphires are an excellent choice of gemstone to use in jewelry for all occasions. Whether it’s a cluster engagement ring or custom earrings for a special occasion, sapphires are a brilliant, versatile, and durable gemstone. While many of the considerations for choosing a sapphire are similar to other gemstones— cut, size, and color— heat treatment can also be a factor in choosing what will best work for you and your style preferences. Although some of our customers prefer the pastel subtlety of an untreated gem, heat-treatment effectively stabilizes sapphires, allowing them to maintain their color and clarity permanently, no matter how many years of wear it gets!

While it’s assumed that a natural gemstone is completely untreated, that is not necessarily the case with sapphires. Heat treatment is very common with sapphires, and generally involves heating a sapphire in a furnace at a temperature around 400 degrees Celsius (or roughly 700 degrees Fahrenheit), to balance and enhance the color and clarity of a gem. This applies to all sapphires across the color wheel, with heat treatment serving to heighten the chroma of green, mandarin, champagne and magenta sapphires alike. While the idea of chemically modifying a stone can be a turn-off to customers, heat treatment is a common practice in the gemstone marketplace. 

Because processing a sapphire with heat enhances its color and clarity without taking away from its quality or durability, it is a common practice in the sapphire trade. Most gems that aren’t noted as being specifically untreated are usually heat treated in some way. Because heating a sapphire forces it to undergo a chemical change, heat enhancement stabilizes the gem’s color and prevents it from changing back to its natural state with time. In many ways, it’s like flash freezing a vegetable or spraying a piece of oil pastel art with a fixative— while it will never be exactly what it was at the start, the process doesn’t negate its natural qualities. Heat treating a colored stone can, in fact, increase its value by producing a more desirable color. Bario Neal sources with the highest consideration for sustainability. We appreciate the beauty of both heat-treated and untreated sapphires. Our sapphires are of Montanan, Australian, Sri Lankan, and Malawian origins— all fully traceable, and all at the highest standard of labor and environmental protections and regulations. We are confident in passing on our traceable origins to our customers. The practice of heating sapphires has been fairly common for hundreds of years. With so many colors to choose from thanks to heat treating technology, we guarantee that your sapphire will be sourced to the highest standard of ethics, sustainability, and quality.