ETYMOLOGY: It comes from the greek "onux" meaning nail.

CRYSTAL SYSTEM: Trigonal.

PRINCIPLE OF FORMATION: Primary.

CLASS MINERAL: Oxides, quartz group

CHEMICAL FORMULA, MINERAL ELEMENTS: SiO2.

HARDNESS: 7 on the Mohs scale.

FIELDS: Italy, Mexico, Brazil, Russia, South Africa, Pakistan.

MINERALOGY: It has a volcanic origin, caused by the accumulation of volcanic gases are varieties of chalcedony, colored bands create black marks on the stone brown, white or have a fine-grained texture. Chalcedony quartz is a form, so that the stones have an aspect onyx and crystalline texture. It is black due to deposits of iron and manganese.

MYTHOLOGY: In ancient times it was considered the stone Unfortunately, generating sadness, fears and hallucinations. It was also believed that he had a demon inside saved and at night went out to sow discord. The name is derived from the Greek word meaning nail. The story is that one day Cupid cut the divine fingernails of Venus with an arrow while she slept, he left the clippings scattered on the sand, and fate turned into stone so that no part of the divine body ever died.

PROPERTIES: It is said that the black onyx promotes stamina, strength and perseverance, helps to learn the lessons imparting confidence and helping to be in harmony with your surroundings, is a stone of protection, due to the way in which repels and deflects negative energy. They are often used in meditation to help people find a deeper spiritual connection and achieve balance.

CHAKRAS: Sacral.

ZODIAC SIGN: Capricorn.

USES: Jewellery, meditation, collection, ornamental stone.