Gemstones that have been given a special facet cut, like the Portuguese cut, refers to a particular type of faceting where a gemstone is cut with two rows of rhomboidal and three rows of triangular
facets above and below the girdle. Since this is only a 'technical' description modified mixed-cuts, which are very common today, may not feature exactly 2 rows and 3 rows as described above, but may have just 1 or 2 rows of mixed rhomboidal and triangular facets. These extra rows of facets are cut into the crown just above the girdle of the stone, which is the line that divides the top of the stone from the bottom pavilion.
The purpose of the extra rows of facets is meant to enhance the brilliance and 'sparkle' of a cut gemstone. Of the many new cutting styles seen with colored stones today, the Portuguese cut is one of the most popular fancy cuts and you'll find many different varieties of gems cut in this manner. Portuguese-cut gemstones will typically have a smaller 'table' at the top-most part of the crown, due to the extra row of facets on the crown. In some cases, a gem that has been poorly cut and exhibits large colorless areas through the table may be 'fixed' by recutting the crown with an extra row of crown facets. Portuguese cut gems can be found in a variety of
gemstone shapes, though oval and round-shape gemstones are most commonly given a Portuguese-style faceting.
Natural tourmaline is one of the most common gemstones that are given this type of special cut. Usually gems with excellent transparency and lighter colors are best for cutting as Portuguese-cut stones, such as
pink tourmaline or
pink spinel. This is because lighter color gemstones will naturally show a higher amount of brilliance and sparkle than those gems with deep, saturated darker colors. Although light and dark color tourmaline stones will have the same gemological properties, lighter color gems and gemstone which have been cut intentionally to favor a lighter color will naturally exhibit more visible brilliance that its darker counterpart. For those seeking something different,
Portuguese-cut gemstones are an excellent option, especially fine natural tourmaline which is almost always never treated or enhanced though artificial processes.
