In today’s post, I am going to attempt to explain cabochons. The word cabochon comes from Middle French caboche (head) and the technique is usually used on opaque stones vs. transparent stones (which are usually faceted). Another consideration for cabochons (often called cabs) is the hardness of the stone (measured on the Moh’s Hardness scale). Softer stones (less than 7 on the Moh’s scale) scratch easily and may be more suited to cabs instead of facets. The cabbing process hides scratches more than faceting would.
Cabochon creation usually begins with a slab of stone. The slab can vary in thickness depending on the maker’s design or how the cab will be mounted. If the setting is closed, the back may not be highly polished and may be hollowed out to reduce weight. If the cage is open, the back may be as highly polished as the top. Cabs are often oval or elliptical with a domed top. Starred (asteriated) stones like cat’s eye or starred sapphire are cabbed so that the star or the cat’s eye will be highlighted. Faceting the stone would not show the feature.
To make a cabochon, a slab of stone of cut on a slab saw.
Once the slab is cut, a template is used to trace out the shape of the cab. A diamond blade trim saw is used to cut away the stone until the rough shape of the cabochon is created. After roughing out the shape, various grit shaping wheels grind away to stone to create the domed top. At the end, a highly polished beautiful cabochon is revealed.
While oval cabs are common, they are by no means the only shapes. As evidenced by the templates shown below, there are many different shapes that can be cabs.
Many local mineral societies and clubs exist and they can help you get started making cabs. I learned the basics at the Georgia Mineral Society and I can’t wait to make another!
In The Gemstone Chronicles Book One: The Carnelian, the carnelian was a cabochon. What is your favorite cabochon stone? Leave me a message and let me know!