Its common knowledge if you're born in July, your birth stone is a ruby, but who says so? So-called "traditional birth stones" were created by jewelers based on what stones they had in overstock at certain times of the year. For example, if you are born in November, Topaz was in abundance, so that became the stone of November people, in order to amp up sales and get rid of extra inventory. Your commercialized birth stone has absolutely nothing to do with you or your birth month. So, what stone does, and why?
The practice of attributing a stone to a certain month and day of the year sprang out of the ancient sciences of Chaldean and Hindu Numerology and Astrology. Our bodies are made up of the same minerals as gemstones and crystals. Each of our cells has a positive or negative magnetic charge, consisting of protons and electrons. Our system is electrical and magnetic. Everything around us has a magnetic charge. When we wear gems, they react with light, altering the electromagnetic field of the body, and thereby creating an electrochemical balance in the body. These stones are charged through exposure to the Sun, Moon, stars and planetary bodies within our solar system, attuning to certain fields of magnetic energy through their color and compositional makeup or structure. In turn, they are connected to specific planets (Sun and Moon included as "planets" here) which individually rule times of the year on our calendar, or months. These gemstones also relate to the day number of the month, as the planets rule certain number vibrations.
What does all this mean? Your month of birth and day of birth are ruled by particular stones of a certain color and increase your good luck.
Here they are:
Born on the 1st, 10th, 19th or 28th of any month - Yellow Topaz, Amber, Yellow Diamond. Also Ruby.
Born on the 2nd, 11th, 20th or 29th - Pearl, Moonstone, pale green stones and Green Jade. Also Clear Quartz, Green or White Agate.
Born on the 3rd, 12th, 21st, 30th - Amethyst. Also Yellow Sapphire, Yellow Topaz.
Born on the 4th, 13th, 22nd, 31st - Blue Sapphire. Also Hessonite (garnet).
Born on the 5th, 14th, 23rd - Diamond, glittery stones, set in Platinum, Silver. Also, Emerald.
Born on the 6th, 15th, 24th - Turquoise and Emeralds. Also, White Diamond, White Sapphire, White Zircon, White Tourmaline.
Born on the 7th, 16th, 25th - Moonstone, Pearl, Moss Agate, Cat's Eye (real not synthetic), set in White Gold.
Born on the 8th, 17th, 26th - Amethyst, Dark Sapphires, Black Pearl, Black Diamond.
Born on the 9th, 18th, 27th - Ruby, Garnet, Bloodstone (if not worn next to skin). White or Red Coral, Carnelian and Jasper.
Other Additional Stones - (in a more general sense and secondary)
January - Moonstones, Pearls, Amethyst
February - Sapphires, Pink Topaz, Moonstone
March - Agate, Sapphire, Amethyst, Emerald
April - Rubies, Garnets, Bloodstone
May - Emerald, Turquoise, Lapis Lazuli
June - White or Red Carnelian, Sapphire, Diamond, Glittery gems
July - Pearl, Diamond, Opal, Cat's Eyes, Clear Quartz, Moonstone
August - Imperial and White Topaz, Amber, Ruby
September - Emerald, Diamond, Pearl
October - Opal, Pearl
November - Turquoise, Ruby, all red stones
December - Amethyst, Sapphire