Most people know that any blue gemstone you see in jewelry is most likely a sapphire. Classic blue sapphire is a stone that exudes sophistication and has often been linked to royalty. Who can ever forget Kate Middleton's stunning engagement ring passed down from Princess Diana?
But, sometimes sapphire gemstones experience abnormal conditions when they are formed that can actually change their crystal structure. And because of this, the world gets to experience a wide range of sapphires stones that differ from the classic blue.
So let's explore the different colors of sapphire and how they are produced:
Most gemstones are allochromatic, meaning that they are colored by impurities or trace elements in their crystal structure. The relationship between chemical impurity and gemstone color is not a simple one.
A gemstone’s color is its most defining and arguably most important characteristic.
Both sapphires and rubies are in the family of gems known as Corundum. Sapphires and rubies are rock-forming minerals and are scientifically the same mineral. Both of these stones are very desirable due to their excellent color, hardness, durability and luster.
The only difference is the trace elements, which give them their rich and different colors. Though Corundum is one of the naturally transparent materials, it can have different colors when impurities are present.
Transparent specimens are used as gems and are called rubies if red. Corundum is typically red when traces of Chromium are present and blue when there are traces of Titanium and Iron. The term “sapphire” applies to all the non-red colors, not just the blue variety.
Transparent colored gemstones are loved for their beautiful colors. How they absorb the visible light that passes through them determines their color. The rainbow array of colors observed in gem materials is directly related to their chemical composition.
Iron produces a lemon yellow color. It is rare for there to be enough Iron in a mineral to generate color.
Iron and Chromium produces a yellow orange color.
Chromium produces a magnificent pink color.
Iron and Titanium produce the desired rich blue color that has been sought after for centuries.
Blending the Cromium (pink) with the Iron and Titanium (blue) will produce a purple color sapphire.
There is also a green colored Sapphire. The options for this stone range from greenish yellow to a bluish teal color. The element causing yellow married with the elements is responsible for the blue color actually produces the green.
The next secondary color is the Padparadsha. It is often referred to the most captivating color. Today, many narrowly define Padparadscha as a sapphire of a very strict and delicate balance of orangy pink and pinkish orange. Other than the Padparadscha, pink sapphires are the most valuable of the fancy sapphires. These are found mostly in Burma (Myanmar) and Sri Lanka.
Due to its exceptional hardness, Corundum is most commonly used as an abrasive. It is crushed to a powder of varying size depending on how rough the grinding stone, cutting tools or sanding paper needs to be. Emery, the most common form of natural corundum used to manufacture abrasives can be up to 60% Corundum.