Available is almost any stone including:
January- Garnet
February - Amethyst
March - Aquamarine
April- Crystal Quartz
May - Emerald
June - Pearl
July - Ruby
August - Peridot
September - Sapphire
October - Tourmaline
November - Citrine
December - Turquoise
also:
Moonstone, Labradorite, Amazonite, Smoky Quartz
Using hypoallergenic Sterling Silver it 14kt Goldfill earring components