How to Identify Blue Stones

turquoise ring image by Vladislav Gajic from

Blue gemstones have an alluring quality of mystery and elegance. From the deep translucence of sapphires to the milky blue of aquamarine, a blue stone enhances jewelry and accessories with their opulence. Identify the blue gems you have by examining a few important characteristics of commonly-used stones. Cut, clarity, color and carat of a stone helps to determine the type and quality of the gem.


Examine the stone. Aquamarine has a light, watery blue color varying in hues from clear blues to a blue-green. The mineral iron contributes to the color of this gem.

Look at the cut. Crystals of aquamarine form in hexagonal prisms. A cut in oval or rectangle shapes help highlight the luster which can range from dull shine like amber to a glassy reflection similar to quartz.

Use a magnifying glass to examine cleavage. The growth of gemstones along a specific plane is called cleavage. The larger the planes, the more the gemstone will refract light. Aquamarine has little to no cleavage.

Blue Diamonds

Feel the stone with your hands and examine closely. Diamonds have a smooth and hard feeling to them. A stone that chips or crumbles easily is not a diamond.

Look for the clarity of the diamond. Diamonds can range from completely transparent in color to dark browns. Diamonds with a pink, blue and green shade are considered the rarest. A high level of transparency indicates a greater value in a diamond.

Inspect the luster of the diamond. Blue diamonds will have an adamantine luster. This means that this type of diamond has a high level of refraction, which bounces off the planes within the diamond to create a sparkling effect.

Look for cleavage within the stone. Blue diamonds should have perfect cleavage or planes that break off in four different directions.


Scrutinize the color. Look at the gemstone to see if it has a blue hue. Sapphires occur in many hues from yellow, purple, green and orange. The most common color of a sapphire is blue.

Hold a magnifying glass up to the sapphire to look for asterism. Needle-like shapes refracting light create a star effect in some sapphires. Sapphires can have six or twelve point stars.

Test the sapphire. These gemstones are very durable and hard. Lab created gemstones and naturally mined stones have very similar qualities. Get the sapphire tested to determine its value.