What Is Chalcedony?

Chalcedony is the family name (like Corundum or Beryl) given to a group of microcrystalline quartzes whose crystals are so small that they appear as a solid mass.

Confusingly it is also the name of one of it’s family members.

This versatile family of stones is often worn and held in very high esteem by many cultures who wear it as a form of protection from the ‘evil eye’.

Working with this family of stones requires immense skill and the German lapidaries of Idar-Oberstein are regarded as the masters of it.

The family of stones has a hardness of 7 on the Moh scale.

Agate… forms in cavities in volcanic rocks usually in nodular masses, on splitting them open the colours and patterns exposed are truly unique.

What Is Chalcedony?

A distinct colourful banding of patterns that vary depending on the impurities present set Agate aside from any other member of this family of stones.

Due to the stones being porous Agate is very often dyed to enhance the natural colouring, Fortification, Dendritic, Moss and Fire Agate are just a few of the most popular varieties.

Blue Chalcedony… has increased enormously in popularity in recent times this beautiful stone can vary from a gentle lilac colour to a more full bodied lavender.

What Is Chalcedony?

The most sought after and best examples of this stone are translucent with prices fairly high, lower grade material can appear cloudy.

Carnelian… is a translucent red orange member of the family which was believed to still the blood and calm a temper.

The colour of this stone can be enhanced by heating and dyeing.

Carnelian has been used for hundreds of years being very popular carved as well as engraved cameos.

Chrysoprase… is a translucent apple green coloured stone and the most valued member of the family, it gets the lush green colour from the presence of nickel.

What Is Chalcedony?

Some Chrysoprase has been known to fade if exposed to sunlight but very high quality material from Australia does not seem to suffer from this problem maintaining it’s full bodied colour.

This stone is very popular cut as a cabochon as well as being used for cameos and beads

Jasper… is a fine grained opaque member of the family with the more popular colour being red but yellow, green and brown colours do exist.

What Is Chalcedony?

Jasper is very often marked strongly by orbicular or striped patterns and looks wonderful polished also a very popular stone used in cameos.

Bloodstone… is a green opaque variety of Chalcedony that is very distinctly spotted red due to the presence of iron oxides.

The spots bearing a resemblance to blood giving the stone it’s name.

Bloodstone looks very good polished and is often used for cameos and beads.

What Is Chalcedony?
Onyx… is similar to Agate but has straight bands rather than curved these are normally brown and white or black and white in colour.

What Is Chalcedony?

For thousands of years Onyx has been stained to enhance or even change it’s colour.

Ironically Black Onyx isn’t Onyx at all, it does not exist naturally, by soaking Agate in a sugar solution and then heating it in sulphuric acid this carbonizes the sugar particles which turns it black.

Sard and Sardonyx… Sard is red brown to orange in colour with Sardonyx being banded Sard with apricot and brown stripes.

What Is Chalcedony?

This material is ideal for inlay work and looks very good polished also popular as cameos and beads.