Birthstone Month:
Chalcedony is not associated with any particular birthstone month.

Zodiac:
Chalcedony is not associated with any particular zodiac sign.

Chemical Symbol:
SiO2

Chemical Make-up:
Chalcedony is a Silicon Dioxide and a cryptocrystalline variety of the mineral Quartz.

History & Lore:
The name Chalcedony is widely believed to be a direct reference to an ancient Greek settlement in Asia minor. Whilst this settlement was known as Chalkedon, modern English usually presents this as being spelled Chalcedon, hence the forming of the name Chalcedony for this gemstone variety.

Chalcedony has been in use almost as long as the earth has been inhabited and some of the earliest primitive tools created by man's ancestors some 2.5 million years ago were made of various types of Chalcedony.  Owing to the huge number of varieties available, Chalcedony soon graduated from being used just for tools, and eventually became a popular material for decorative purposes and jewelry adornments.

Chalcedonies are believed to have been considered sacred stones by Native American Indians and they were often used for ceremonial purposes, particularly for promoting stability within the tribes.

Chalcedonies are believed to promote charity, improve relationships and enhance the wearers ability to offer kindness to others, as well as irradicating feelings of hostility, negativity and irritability. Chalcedonies are also credited with having the ability to promote emotional balance and to improve the wearers vitality and stamina.

Sources:
Chalcedony deposits occur worldwide.

Evaluation:
Chalcedonies varieties are rated at 6.5 - 7.0 on the Moh's Scale of Hardness, making all Chalcedony suitable for most jewelry applications. The sheer amount of colors and individually identifiable varieties that Chalcedonies are found in is immense, and because of this, different varieties of Chalcedony have been awarded different descriptive names.

It can appropriately be said that any member of the Chalcedony family that exhibits a shade of orange can be categorized as an Orange Chalcedony. Such members include Jasper, Agate, and the popular reddish-orange variety of Chalcedony known as Carnelian.

Generally the value of an Orange Chalcedony is determined significantly by the fashioning of the stone, with color saturation, level of translucence, and distinctive patterns also being important factors depending upon the Chalcedony selected.

Common Cuts:
Cut is a very crucial trait and has a huge effect on the overall look and perceived value of Chalcedony. Chalcedony varieties are often found carved into decorative items and in jewelry, Chalcedony is most commonly found fashioned into beads, or cut into Cabochon form, but many can actually be cut into most of the common gemstone shapes/cuts.

Routine Enhancements:
Chalcedonies are routinely dyed in order to improve and enhance color.

Care & Cleaning:
Chalcedony varieties are generally best cleaned using warm soapy water and a soft brush. As with most gemstones, Chalcedonies should be kept away from household chemicals and from prolonged exposure to extremes of heat as this can cause damage or permanent changes in coloration. Chalcedonies should be kept in a fabric-lined box away from other jewelry items in order to avoid damage / scratching.