09/11/2026
Love blue gemstones but want something suited for regular wear? Save this list!
These gems rank 7 or higher on the Mohs hardness scale, making them more resistant to everyday scratches.
- Blue diamond: With a Mohs scale rank of 10, ultra-rare and brilliant, blue diamonds are the hardest blue gemstones. Its color gives it a mysterious aura, as does its occasional red fluorescence.
- Sapphire: Sapphires have Mohs scale rank of 9 and are a true-blue classic. Its most popular colors are a rich royal or cornflower blue.
- Cobalt spinel: Among the rarest blue gemstones, cobalt spinel ranks 8 on the Mohs scale. Trace amounts of cobalt create its vibrant blue color, making it highly sought after by collectors.
- Blue topaz: One of the most popular blue gemstones, blue topaz ranks 8 on the Mohs scale. It is known for its vibrant sky, Swiss and London blue hues and remains one of the most affordable options.
- Aquamarine: Best known for its tranquil greenish blue to blue color, aquamarine ranks 7.5–8 on the Mohs scale. Long associated with the sea, it was once believed to protect sailors and calm the waves.
- Paraíba tourmaline: Famous for its extraordinary neon blue to blue-green color, Paraíba tourmaline ranks 7–7.5 on the Mohs scale. Its electric glow is caused by trace amounts of copper, making it one of the world's most coveted tourmaline varieties.
See the full list of must-know gemstones on our website: https://bit.ly/4y14ARV
