Onyx is known to separate. It can help release negative emotions such as sorrow and grief. It is used to end unhappy or bothersome relationships. Onyx guards against negativity. Onyx jewelry is worn to defend against negativity that is directed at you. Black stones have protective energies in the sense that black is the absence of light, and therefore, can be used to create invisibility.
A plain, yet elegant example of Mexican craftsmanship. This lovely pair of clip-style earrings consist of an oval onyx cabochon mounted an etched bezel surround. The earrings measure 7/8" in length and 5/8" in width. Each piece is stamped "Mexico, 925, TZ20". The condition is near mint with nice original patina.
Circa 1979 a new letter/number mark to indicate the silversmith and sterling standard was introduced in Mexico. The first letter indicates the city/area location "T". The second letter is the first initial of the last name of the silversmith (Z). The last number(s) indicates that he is the 20th silversmith with a last name beginning with that letter to register at the city assay office.