Pink Tourmaline engagement rings? Absolutely! Diamonds may be a girl's best friend, but Pink Tourmaline engagement rings are a unique, original, and a far more affordable choice. Pink tourmaline is a birthstone of October, along with opal, and is a truly special gem. The deep rosy color of a pink tourmaline ring will be sure to attract attention. Sapphire is the birthstone of September, and pink sapphire is a very popular gemstone in jewelry today. The bright and happy color of a pink sapphire ring is both playful and trendy.