Smoky Quartz engagement rings? Absolutely! Diamonds may be a girl's best friend, but Smoky Quartz engagement rings are a unique, original, and a far more affordable choice. Brown gemstones are gaining in popularity and smoky quartz is an affordable choice. A smoky quartz ring goes well with autumn colors and evening wear. 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.