Color / Hardness / Clarity / Refractive Index / Specific Gravity / Fluorescence
- Color: Observe the color of the gemstone under different lighting conditions. The color can give you a clue to the type of gemstone it may be. For example, a red stone could be a ruby, a blue stone could be a sapphire, and a green stone could be an emerald.
- Hardness: Test the hardness of the gemstone using a Mohs (Mohs scale) hardness test kit or a scratch test. The hardness of a gemstone can help identify it because different minerals have different levels of hardness. For example, diamonds are the hardest mineral with a rating of 10 on the Mohs scale, while talc is the softest mineral with a rating of 1.
- Clarity: Use a magnifying glass or jeweler’s loupe to examine the gemstone for any inclusions or blemishes. Inclusions are internal imperfections, while blemishes are external imperfections. The clarity of a gemstone can help identify it because different gemstones have characteristic inclusions and blemishes.
- Refractive index: Test the gemstone’s refractive index using a refractometer. The refractive index is a measure of how much light is bent as it passes through the gemstone. Different gemstones have different refractive indexes, which can help identify them.
- Specific gravity: Measure the specific gravity of the gemstone using a density kit. The specific gravity is the ratio of the weight of the gemstone to the weight of an equal volume of water. Different gemstones have different specific gravities, which can help identify them.
- Fluorescence: Observe the gemstone under ultraviolet light to see if it fluoresces. Some gemstones fluoresce in different colors, which can help identify them.