Black agate is a form of chalcedony which is a form of Quartz crystal. Black agate stone is found all over the world with the biggest mines in Brazil, Mexico, United States, Uruguay, and Madagascar. Black agate is associated with the zodiac sign of Gemini.
Zircon is a tetragonal crystal, similar to druzy crystal which occurs in different shades and combinations of yellow, brown, green, black, gray, and red, and is often colorless. Thailand, Sri Lanka, Austria, Australia, Cambodia, Myanmar, Bangkok, Nigeria, Madagascar, Norway, Afghanistan, Mozambique, France, Vietnam, Pakistan, and Canada all have rich deposits of Zircon Crystal, while it is easily available in many other parts of the world too. The meaning of the zircon birthstone is wisdom, prosperity, and confidence. Zircon symbolizes these traits and is thought to aid in sleep quality and warding off evil spirits. During the Victorian era, this December birthstone was a prized gem, often adorned in necklaces and other decorative pieces.