Why Are Some Gemstones Cut As A Cabochon?

Bright Ruby Cabochons from the Taita region of Kenya

 

Cabochon Vs Faceted?

 

A Cabochon (or cutting en cabochon – French: “in the manner of a cabochon”) is a type of cut used on gemstones where by the stone is shaped and polished into a smooth, generally convex shape with a flat base. Cabochons or Cabs are generally circular or oval but may be cut into different shapes.

Cabochon Polishing at our Lapigems Gem Cutting Center

 

Cabs are usually used on softer species, such as Opal or Moonstone (Mohs Scale of Hardness), on opaque gems or gems of a lower grade. Gem cutting is a fine art and is done to enhance the gems natural qualities and transform it into a piece that best displays these attributes. Cabochons often act like a window, allowing one to see the gems natural details inside and display other visual effects such as play of color in Opals, cat’s eye and asterism (star). Cabochons are more likely to have natural inclusions and markings.

 

 Cabochon cutting dates back to the Middle Ages and has remained a popular cut ever since.

Faceting is another form of cutting a gemstone. An ancient art where by a gem is methodically cut with numerous flat surfaces using the appropriate or critical angles of the gems structure on the top and bottom of the stone, this is to allow light to refract and reflect through the gem to enhance its brilliance and give the stone its sparkle. The more facets a stone has, the more “lively” a gem will be.  Faceted gems have polished flat faces (the table) and pointed bottoms (the pavilion). For further information on gem cutting please see our Gemstone Cutting article.

Faceted cuts are generally used on harder gemstones (Mohs Scale of Hardness) that are transparent or “clean” and for fine gems as any inclusion or markings would disturb the light passing through the stone and therefore decrease its beauty.

Faceted Tourmaline from Lapigems Rare Gemstone Company

 

Faceted stones are available in many forms, the four most common being Brilliant Cut, Step Cut, Drop Cut and Mixed Cut. Different shapes are cut using these different forms.

It was only until the 15th Century that faceting gemstones was possible, as the abrasive properties of Diamonds was discovered and used.  Master Cutters us Diamond powder on cutting machines and proper knowledge of the crystals structure to ensure top cutting. This is done at a sacrifice, as often up to 30% of the stone is lost, however the value of the gem is greatly improved as a result.

  

Gemstone faceting at our Lapigems Gem Cutting Center

 

At Lapigems Rare Gemstone Company we have been cutting colored gemstones since we started in 1974. Our first Master Cutter was taught by a German Master Cutter and since then we have been teaching and training up new cutters in this fascinating ancient art.

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