Color Variations:
Black Onyx: The most well-known variety, prized for its deep black color.
Sardonyx: A variation with bands of brownish-red and white.
Properties:
Hardness: Onyx ranks 6.5 to 7 on the Mohs scale, making it relatively durable for use in jewelry.
Luster: It has a glossy, vitreous luster that enhances its visual appeal.
Transparency: Onyx is generally translucent to opaque.