Synthetic Sapphire

About Sapphire

The birthstone of September is Sapphire gems. Sapphire is a gemstone, a variety of corundum, a crystalline form of aluminum oxide (AL2O3). The color of corundum can be blue, pink .yellow, orange, green, colorless, etc. The color of the corundum depends on the trace metal like copper, magnesium, iron, chromium, titanium. Corundum of all color is called as sapphire except red sapphire. Red corundum always is known as Ruby. The color of Ruby is pink to blood-red because of the element chromium.

About Synthetic Sapphire

Synthetic sapphire was first found in 1902 by the French chemist Auguste Verneuil.  A synthetic sapphire gems material is one that is made in laboratory, which is the same as natural mineral counterpart in some way like chemical, optical and physical characteristics. Synthetic sapphire have their own quality grade as A, AA, AAA. Synthetic sapphire can come in the shape of oval, round, trillion, square, heart, etc. In addition, some companies, mainly producing synthetic gemstone, can customize the shape and size of synthetic sapphire according to your requirement. As a general rule, synthetic sapphire always more perfect than traditional sapphire because they don’t contain the impurities. Since there is not enough natural sapphire to meet demand, various synthetic gems have appeared in the market over the last few decades. Although there are many colors in synthetic sapphire, blue synthetic sapphire is the most popular. Synthetic sapphire is too similar to identify them. In general, an experienced jeweler can identify them. Sapphire is a rare, valuable and most precious gemstone. If a nice sapphire is too cheap, it must be synthetic.

Process of Producing Synthetics

Synthetic Sapphire is grown in furnaces. Taking Aluminum oxide in the furnace and heating it to about 2050 degrees Centigrade and then cooling it. When it cools it forms a sapphire crystal. There are many process to create sapphire : melt growth, solution growth, extremely high-temperature, high-pressure growth processes, floating zone process, the flux process and the hydrothermal process. With the advancement of science and technology, the method of making synthetic gemstones will become more and more complete. Today, it’s estimated that about 90%-95% of the sapphire in the market are heart-treated.

Use of Synthetic Sapphire

At present, synthetic sapphire is used extensively in sterling silver sapphire jewelry making such as sterling silver sapphire rings, sterling silver sapphire earrings, sterling silver sapphire pendants, sterling silver sapphire bracelets. Affordable price synthetic sapphire jewelry can meet market demand. Synthetic sapphire also can be used in the watch and semi-conductor industries. Sapphire is the second hardest gems in the word. The Mohs scale of sapphire is more than 9, thus being quite scratch resistant. That is why the sapphire used in watches. In the future, it will be used in IPHONE to protect the mobile phone screen.

Properties of Synthetic Sapphire:

Crystal System Hexagonal
Lattice a=4.785Å, C=12.991Å
Density 3.98g-4.10g/cm3
Purity 99.99%
Transmission Range 170-6500nm, >80% in IR range
Melting Point 2040°C
Specific Heat 0.418 W.s/g/K
Thermal Conductivity 25.12 W/m/K
Thermal Shock Resistance 790 W/m
Thermal Expansion Coefficient 5.8×10-6/K
Dielectric Constant 11.5°C (Parallel to the c-axis)

103-1010Hz 25

9.3°C (Perpendicular to the c-axis)

103-1010Hz 25

Hardness 9 Mohs
Refractive Index 1.83 @0.26 m, 1.76 @0.63 m, 1.58 @5.57 m