How to Identify Rough Sapphire

Sapphire is a beautiful and valuable gemstone that comes in a range of colors, from blue to pink to yellow. Identifying rough sapphire can be challenging, as it can resemble other minerals and stones. In this article, we will discuss the characteristics of rough sapphire and the methods that can be used to identify it.

What is Rough Sapphire?

Rough sapphire is a naturally occurring mineral that belongs to the corundum family. It is typically found in igneous and metamorphic rocks, as well as alluvial deposits. Rough sapphire can range in color from blue to pink to yellow, and may contain inclusions such as rutile or iron.

Visual Inspection

The first step in identifying rough sapphire is to conduct a visual inspection. Rough sapphire is typically opaque or translucent and has a vitreous or adamantine luster. It may appear blue, pink, yellow, or green, and may have a hexagonal or trigonal crystal structure. Inclusions such as rutile or iron may be visible under a loupe or microscope.

Hardness Test

Sapphire is one of the hardest minerals on the Mohs scale, with a rating of 9. A simple scratch test can be used to determine if a mineral is sapphire. Take a piece of glass or a steel file and scratch the surface of the mineral. If the mineral scratches easily, it is likely not sapphire.

Density Test

Sapphire has a high density, which means that it is heavier than most other minerals of the same size. A density test can be used to determine if a mineral is sapphire. Weigh the mineral and measure its volume, then calculate its density. If the density is high, it may indicate that the mineral is sapphire.

UV Light Test

Sapphire fluoresces under ultraviolet light, which means that it emits a distinctive glow when exposed to UV light. A UV light test can be used to identify sapphire in a mineral. Place the mineral under a UV light and observe whether it fluoresces. If it does, it may contain sapphire.

Heat Conductivity Test

Sapphire has a high thermal conductivity, which means that it conducts heat quickly. This property can be used to distinguish sapphire from other minerals. A thermal conductivity test involves heating the mineral and measuring how quickly it cools down. If the mineral cools down quickly, it may contain sapphire.

X-Ray Diffraction Test

X-ray diffraction is a method used to identify the crystal structure of minerals. This test can be used to determine if a mineral contains sapphire. X-ray diffraction involves passing a beam of X-rays through the mineral and analyzing the diffraction pattern. If the pattern matches that of sapphire, it may indicate that the mineral contains sapphire.

Conclusion

Identifying rough sapphire can be challenging, as it can resemble other minerals and stones. Visual inspection, hardness tests, density tests, UV light tests, heat conductivity tests, and X-ray diffraction tests are all important tools that can help to identify rough sapphire. If you believe you have found rough sapphire, it is important to handle it with care and seek the advice of a professional gemologist or mineralogist.