Featuring one of the widest color ranges of any gem, tourmaline is one of October’s two birthstones. A favorite of mineral collectors everywhere, tourmalines come in all shapes, sizes, color saturations and tones – from expensive electric blues to affordable olive greens.

If you’re in the market for one, you’ll want to check out GIA’s Tourmaline Buying Guide for some can’t-miss tips and advice. Learn why color is the most important quality factor, how to care and clean for your tourmaline, and more colorful facts.

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