By her who in January was born No gem save garnets shall be worn
They will ensure her constancy True friendship and fidelity.

The February born shall find Sincerity and peace of mind,
Freedom from passion and from care, If they, the amethyst will wear.

By her who in March was born No gem save Bloodstone shall be worn
They will ensure her constancy True friendship and fidelity.

She who from April dates her years, Diamonds shall wear,
lest bitter tears For vain repentance flow.

Who first beholds the light of day In spring's sweet, flower month of May
And wears an Emerald all her life Shall be a loved and a loving wife.

By her who in June was born No gem save Pearls shall be worn
They will ensure her constancy True friendship and fidelity.

The gleaming Ruby should adorn, All those who in July are born,
For thus they'll be exempt and free, From lover's doubts and anxiety.

Wear a Peridot or for thee, No conjugal fidelity,
The August born without this stone, `Tis said, must live unloved; alone.

A maiden born when autumn leaves Are rustling in September's breeze,
A Sapphire on her brow should bind; To bring her joy and peace of mind.

October's child is born for woe, And life's vicissitudes must know,
But lay an opal on her breast, And hope will lull those woes to rest.

Who first comes to this world below In dreary November's fog and snow,
Should prize the topaz amber hue, Emblem of friends and lovers true.

If cold December gave you birth The month of snow and ice and mirth
Place on your hand a turquoise blue; Success will bless whate'er you do.

—Gregorian Birthstone Poems

In 1912, in an effort to standardize them, the American national association of jewelers, Jewelers of America, officially adopted a list, shown in the "Modern" column in the table below. It is currently the most widely used list in the United States and many other locations, including Australia and Thailand. Some alternates have been adopted to be a less expensive substitute for a cut stone. Tanzanite was added to December by the American Gem Trade Association in 2002.

Month	Traditional Birthstone(s)[3]	Modern Birthstone(s)[3]
January	garnet	garnet
February	amethyst	amethyst
March	bloodstone, jasper	aquamarine
April	diamond, sapphire	diamond, white topaz
May	emerald, agate	emerald
June	alexandrite, emerald	moonstone, pearl
July	ruby, onyx	ruby
August	sardonyx, sapphire	peridot
September	sapphire, peridot	sapphire
October	tourmaline, aquamarine	opal, tourmaline
November	citrine, topaz	topaz, citrine
December	zircon, ruby	turquoise, blue topaz

Birthday stones

While this word has also been used as synonym of Birth stone (see above), there is a separate list of assignment according to the day of the week of the recipient's birth:

• Monday : Pearl
• Tuesday : Garnet
• Wednesday : Cat's eye (Chatoyant Chrysoberyl)
• Thursday : Emerald
• Friday : Topaz
• Saturday : Sapphire
• Sunday : Ruby

And just in case you want birth flowers to go with those birthstones:

Birth flowers

Month	Flower
January	Carnation, Snowdrop
February	Violet
March	Daffodil (Jonquil)
April	Daisy, Sweet Pea, Tulip
May	Sunflower, Lily of the Valley
June	Rose, Honeysuckle
July	Larkspur
August	Lily, Gladiolus
September	Forget-me-not, Morning Glory
October	Calendula (Marigold), Camellia
November	Chrysanthemum
December	Holly, Narcissus