Onyx is a variety of chalcedony quartz that features a fine texture with a smooth black color. Some onyx can display white bands or ribbons against black or brown backgrounds. Mined in Brazil, India, California and Uruguay, most onyx today is color-enhanced to increase its depth of color. It ranks a 6.5 on the Mohs Scale and is an ideal stone for carving. In fact, it is a favorite material of lapidary artists.
Onyx was very popular with the ancient Greeks and Romans. The name comes from the Greek word “onux,” which means fingernail. Legend says that one day frisky Cupid cut the divine fingernails of Venus with an arrowhead while she was sleeping. He left the clippings scattered on the sand and the fates turned them into stone so that no part of her heavenly body would ever perish. In Greek times, almost all colors of chalcedony were called onyx. Later, the Romans narrowed the term to refer to only the black and dark brown colors, while the reddish brown and white onyx became known as sardonyx. Highly valued in Rome, sardonyx was especially used for seals because it was said to never stick to the wax. Roman General Publius Cornelius Scipio was famous for wearing sardonyx.
Worn during mourning in the Victorian age, onyx is now traditionally given as a 7th wedding anniversary gift. It is thought to increase happiness, intuition and instincts. The stone is also believed to cool the yearnings of love and decrease sexual desire.
Earring Back Types
The backing is an important part of an earring, providing a secure closure and comfortable fit. Keep in mind, some earring styles work better with certain back types. Experiment with the different types to find the best fit for you!
Butterfly Back: A double looped piece resembling a butterfly that fits over a post. Variations on this design are called push back clasps. The basic post and butterfly back are usually used for stud earrings and lighter weight drop earrings.
Hinged Snap Backs: This clasp features a hinged post that snaps into a groove on the back of the earring. It is commonly found on hoops. Sometimes the hinged post is curved to provide more room to fit around the ear, sometimes called a saddleback.
Hook Backs: This earring backing is simply a long, bent post that fits through the piercing. Hooks have several variations, most notably the shepherd's hook and the French hook. While thin wire hooks reduce the weight of long earrings, making them more comfortable, they aren't as secure as other clasp styles.
Lever Back: A hinged lever snaps shut against the curved post to form a closed loop around the ear lobe. This clasp is very secure and good for large or medium sized styles that drop just below the ear.
Omega: Also called French clips, this clasp has a straight post and a looped lever. The hinged lever closes around the post and is held against the ear with pressure. The omega clasp is the most secure clasp, especially for the larger, heavier earrings.
Screw back: This backing is a slight variation of the standard post and butterfly nut back. Instead of pushing on the back, the nut twists onto the threaded post. A screw back post design is often preferred for expensive diamond stud earrings that require increased security.