January - Almost all sources are consistent in stating that garnet

is the birthstone for January.

February - Most sources agree on the amethyst as February's

birthstone, but a few list pearls.

March - Older sources were divided between jasper and bloodstone

as the appropriate birthstone.

April - Sapphires were often listed as April's birthstone.

May - May has a lot of choices for birthstones: emeralds, agates,

chalcedony or carnelian.

June - Birthstone choices include emerald, agate, chalcedony, turquoise,

pearl, moonstone and cat's-eye.

July - The most common birthstone for July in older sources is the onyx. 

Other birthstone candidates include sardonyx, carnelian, ruby and turquoise.

August - Besides peridot, someone born in August could choose

carnelian, sardonyx, moonstone, topaz or alexandrite as his or her

 birthstone.

September - Birthstones could be chrysolite or sardonyx as well as

 sapphire.

October - Although opal is the traditional birthstone for October, alternatives i

nclude tourmaline, beryl and aquamarine.

November - Most older sources agree on topaz, but at least one gives

pearl as an alternative birthstone.

December - In past times, December's birthstone was most commonly

listed as ruby.  Turquoise and bloodstone were other choices.  Lapis

lazuli is also cited.