Buying gemstones by shape is often eye-opening versus buying gemstones by type. In most cases, gem dealers will have many gemstone types that you may not have even heard of before. If you're open to the idea of any color gem and any gem type, as long as it's in the right shape and size, then shopping gems by shape is a great way to provide you with more options to choose from. In the gemstone world, shape and cut are different concepts, but the difference isn't always obvious, making sense of the two is often too confusing, even for professionals in the gem industry. The shape of a gemstone refers to exactly that; the face-up outline of a specific gemstone.
The most common shapes for finished gemstones are round, oval, square, marquise, baguette, cushion, heart and etc. For square-shaped gemstones, princess-cut gems are most popular, cut with a 1:1 length-to-width ratio. Square-shaped faceted gems may also be step-cut rather than brilliant-cut as seen in the princess-cut style. Brilliant-cut gems are designed to bring out the brilliance in a gem, whereas step-cut gemstones establish more emphasis on bringing out the natural color of a gem. There are even several mixed cut-styles that feature an overall square shape, perhaps featuring facets on the pavilion combined with a smooth, domed crown. Examples of mixed-cut gemstone styles include rose-cut gems, buff-top gems and checkerboard-cut gems. Square shapes gems are also offered as square cabochon gems. Square cabochons are usually domed, but unlike oval and round cabochons, square shapes often come to a crease due to the overall shape of the gem.