For the new readers of this blog, this month we have again our Gemology Expert María Isabel Sallent, Jeweler and Gemologist from Barcelona, Spain. He studied Jewelery at the prestigious Massana School in Barcelona, and later studied Gemology at the University of Barcelona, where he graduated in the Specialties of Natural, Treated and Synthetic colored Gem, and also in Diamond.
During his long professional career he has collaborated as a columnist with the most important specialized newspapers of the Jewelery Sector in Spain such as Contrast, Arte y Joya from Grupo Duplex and Gold and Time . Currently he writes in his Blog La Niña de las Piedras, manages an important group on Facebook “Association of World Gemologists”. He belongs to the board of directors of the Association of Gemologists of Barcelona. And in this article he will talk about the Onix , or Onyx.
The name Onyx should be reserved for Chalcedony with black and white streaks. Layered material used in glyptic, it is used using a light layer over dark, the normal thing is that it is engraved in a two-layer stone or as a rare thing in a three or five layer. We also find Sardinian Onyx, a brown undercoat, and the Carnelian Onyx. On the other hand, the same name is used for single-colored Chalcedony, for example Black Onyx, which should not be confused with Onyx marble, which is also called Onyx for short.
It is a translucent limestone composed of calcite and aragonite. It is used for industrial art objects, pendants and brooches. Its hardness is 3 much softer than Onyx, it would not serve to engrave as a jewel due to the strong wear.
Agate is a variety of Chalcedony, which in turn is a variety of quartz, crystallizes in the trigonal system with a microcrystalline habit, and with a hardness of 6.5 to 7. There are some varieties, which actually they are Chalcedonies with different inclusions such as dendritic agate, mossy agate or mocha stone, landscape agate, onyx or onyx, fire agate, sardonix, black onyx.they receive these names because of the colors and patterns of their bands.
Carnelian Onyx, a variety with black and red bands that can also alternate with bands of gray and white Chalcedony.
Chalcedony onyx, the black areas here alternate with other bluish gray and white. The bluish tones are achieved with a very thin white top layer (due to the scattering of light, and the transparency of the black background). This is occasionally called “niccolo”. This variety of Onyx is used to work in cameos, taking advantage of the clear bands to sculpt the figure. They are highly prized as stamps and for engraving shields and monograms.
The engravings in depth are called gems, those with negative drawing, such as those used for seals, intaglios, and those with carved drawings cameos.
It is not easy to find banded agates for this work in natural colors, so they are often dyed.
Cameo of Ptolemy II
1925 cameo made in Torre del Greco and exhibited in the Museo del Corallo.
There are doubts as to whether the term onyx comes from the Hebrew schoam (nail), or from the Greek lapus onyx (literally, stone-nail), but the Hellenic legends attribute its origin to the fact that “…Eros had broken a Aphrodite’s nail while she slept and had thrown it into the water; but since not even the slightest fragment of an immortal’s body can die, the Fates turned it into stone and so it continued to live, grow and reproduce… “.
The truth is that in ancient times onyx was highly valued, but with the passage of time its fame suffered a notable setback: the Romans made pins, seals and earrings with it engraved with the signs of the Zodiac, using them as talismans, while in the Middle Ages, perhaps due to Arab influence, onyx became a herald of misfortune, poverty and bad luck. In the 15th century England things changed, it was used as an amulet against night terrors and evil spirits.
Opinions on the virtues and properties of onyx were always very divided: while the positive tradition sees it as the stone par excellence to combat melancholy, extinguish disastrous passions, combat bad dreams and hallucinations and instill lofty thoughts, for Alexander Magno, the onyx “… can cause pain and vertigo, awaken horrible night terrors and sow discord among friends and family. Worn next to the body, it causes heaviness, sadness, nightmares, miscarriages and premature births…”.
Mandeville, instead, opts for an ambiguous middle term: “…it is true that onyx attracts spirits and demons, but in return it gives the necessary courage to confront them…”
The Onyx has a Projective energy, being associated with the planets Mars and Saturn, its element is fire, its deity Mars and its associated stone the Diamond.
In former times it was said that it was the manifestation of a demon imprisoned in the stone, which woke up at night and frightened the people within its reach.
Basically like most black gemstones, it is a gem of protection and defense against conscious negativity directed at us.