Onyx Stone with a Long History
The mineral onyx is a natural stone used for a wide variety of different purposes including fireplace surrounds, household furniture and ornaments. The finest grade material is often transformed into gemstones but with that said, there's a huge amount of confusion surrounding the use of the name onyx. In the vast majority of cases particularly in relation to gemstones and material used for decorative purposes, the name is used incorrectly.
Onyx is a black and white banded variety of the mineral agate or an agate that exhibits just one colour but has alternating light and dark coloured bands (often black and white). Although onyx and agate are both varieties of the mineral chalcedony (a microcrystalline variety of quartz), the main difference between the two is the bands in onyx are parallel whilst those in agate are curved. Microcrystalline is a term which describes crystals so small they can't be seen with the naked eye.
Most stones labelled as black onyx are usually a black coloured agate or chalcedony because natural black onyx is pretty rare. Since antiquity the vast majority of black onyx has been dyed. In one respected publication relating to gemstones it's stated in order to achieve the colour black stones are soaked in sugar or honey before being treated with sulphuric acid.
In his encyclopedia Naturalis Historia [circa 77-79 AD] Roman author and naturalist Pliny the Elder speaks at length about techniques used to change the colour of one gemstone to make it look like another.
There is considerable difficulty in distinguishing genuine stones from false; the more so, as there has been discovered a method of transforming genuine stones of one kind into false stones of another. Sardonyx, for example, is imitated by cementing together three other precious stones, in such a way that no skill can detect the fraud; a black stone being used for the purpose, a white stone, and one of a vermilion colour, each of them, in its own way, a stone of high repute. Nay, even more than this, there are books in existence, the authors of which I forbear to name, which give instructions how to stain crystal in such a way as to imitate smaragdus and other transparent stones, how to make sardonyx of sarda, and other gems in a similar manner. Indeed, there is no kind of fraud practised, by which larger profits are made.
Ref; (Pliny's Naturalis Historia chapter 75).
The history of the stone onyx can be traced back much further than Ancient Rome and is believed to have been one of the gemstones in the high priest breastplate. This biblical garment was worn by Aaron the first Jewish high priest over the top of a tunic-like garment. Onyx was believed to have been the second stone in the fourth row with a beryl to its left and a jasper to its right.
Much of the banded onyx used for decorative purposes so items like chess sets, figurines and even tumbled stones are often banded calcite. The reason for using this stone instead is simply because it's more readily available. Furthermore calcite is much softer which means it's also easier to work with. On mohs scale of mineral hardness onyx grades 6.5 to 7 whereas calcite grades 3.
Ruby is the traditional birthstone for the month of July with onyx being the alternative.
Onyx Healing Properties
When used for its healing properties onyx provides strength and support especially in difficult and stressful situations. It helps you to be the master of your own destiny and promotes vigor, stamina and determination.
Onyx holds on to memories so can be used to delve into past lives. It may be used for dealing with grief, strengthening self control and for stimulating the power of good decision making. It boosts self confidence, helps with phobias and balances the yin and yang energies within the body. Onyx is a stone for the present but one that carries with it happy and positive memories from the past.