• The month of December that includes the zodiac signs of Sagittarius and Capricorn has an assortment of 11 stones listed as birthstones.
• The birthstones marked for December are turquoise, blue topaz, tanzanite, zircon, lapis, onyx, ruby, and chrysoprase.
• The zodiac signs add on five more birthstones: agate, garnet, amethyst, sapphire, and beryl.

The featured birthstone, Turquoise has its name derived from the French language either from the word for Turkish (Turquois) or dark-blue stone (pierre turquin). This stone is one of the first gems to be used in jewelry.

Turquoise is an opaque, blue-to-green mineral that is a hydrous phosphate of copper and aluminium, with the chemical formula CuAl₆(PO₄)₄(OH)₈·4H₂O. It is a porous stone with hardness lying from 5-6 on the Mohs scale. It is cryptocrystalline i.e. the crystals can only be seen through a microscope. The color of this gemstone varies from white to sky blue and also blue-green to yellowish green. At times, Turquoise may also be peppered with flecks of pyrite or interspersed with dark, spidery limonite veining.

Turquoise is typically found in arid regions, inside cavities and fractures in typically highly altered volcanic rocks, often with associated limonite and other iron oxides. It has been recovered as a byproduct of large-scale copper mining operations, especially in the United States. Persia in Iran has been the largest and most consistent source of this gemstone. Other minor deposits occur in China, Australia, Afghanistan, Northern Chile, Cornwall, Saxony, Silesia and Turkestan.

• Turquoise is considered as the national stone of Persia and has been extensively used to highlight objects as well as architecture.
• Turquoise is sacred to many Native American's specially North American Indians. They carved it into animal and bird shapes and placed them in tombs to safeguard the dead and attract beneficial spirits. Tibetans also consider it sacred.
• It was used for healing purposes by medicine men in the past and fixed on their bow by warriors for accurate shots.
• The gemstone was so revered in ancient Mexico that mere mortals were not permitted to wear it and it was reserved for the Gods.
• A common belief shared by many of the civilizations held that turquoise possessed certain prophylactic qualities; it was thought to change color with the wearer's health and protect him or her from untoward forces.
• A belief commonly accepted by all cultures is that the sky blue stone that is naturally formed by the earth reminds us of our deep connection with the earth and the sky.

• It is used to commemorate the 5th and 11th wedding anniversaries.
• A gift of Turquoise represents friendship and luck.
• Turquoise attracts money, success and love, wisdom and strength.
• It is believed that the gemstone changes its color when worn by a sick person becoming pale and regains it back once the person becomes fit and fine.
• It is really beneficial for problems of the respiratory and immune system. And strengthens the entire anatomy.
• Turquoise draws out negative vibrations from a person and should be placed near the feet as it allows the negativity to go back into the ground.
• Turquoise brings in a feeling of unconditional love keeping us grounded to our family and roots by way of deep emotional attachments.

Blue topaz is another birthstone for the month of December. Its name is derived from the Sanskrit word 'tapas' meaning fire. It is found in Brazil, Sri Lanka, Russia, Australia, Africa, Mexico and Pakistan. This gemstone is known for its healing powers specially for curing asthma, weak vision and insomnia. It was also believed to be endowed with magical properties and was believed to make the wearer invisible. It is used to commemorate the 4th, 19th and 23rd wedding anniversary.