From Rough to Polished: Portuguese Cut

“… having reached the level of complexity involved in faceting the Portuguese cut has made it a lot more easier for me to carry out the styles that followed since no other fancy cut styles would have this many facets!”

Taiwan has been in semi-lockdown for almost a month now. As a result, the writer’s adventure in learning gemstone faceting has unfortunately come to a pause. On the bright side, it’s also a time for me to reflect a bit on the savoir-faire that I’ve acquired and developed over the past five months since — as someone once said — taking a break may lead to breakthroughs.

Looking back, the time when I finished my first Portuguese cut also marks a turning point in my ‘brilliant’ adventure. Why? Portuguese cut is perhaps the most challenging gem cutting style that I’ve ever come across; challenging not in terms of its difficulty but complexity, which made the process exceedingly time-consuming and repetitive that I nearly lost my patience.

What is Portuguese cut?

Before going into details, you diligent readers would have asked: so what is a Portuguese cut? While the standard round brilliant cut has 57 facets, a Portuguese cut can have up to as many as 161 facets. In a nutshell, the style comes with a deep cut with rows of rhomboidal and triangular facets.

Diagram of Simple Portuguese Cut by Jeff Graham
Courtesy ofInternational Gem Society

Due to the great number of facets it has, it’s no surprise that a Portuguese cut yields wonderful display of light and probably more scintillation (the patterned flashes of light seen when the stone is moved) than almost any other gem cutting style. Portuguese cut tends to have a smaller table (the top horizontal facet), encircled by rows of rhomboidal to form the crown (the upper portion of the stone), enhancing the overall brilliance of the stone.

Occasionally, Portuguese cut is used for larger coloured stones. The nature of this cutting style can hide small inclusions in the stone, enriching a light-coloured gemstone with more colour and sparkles. Depending on the situation, the number of rows of rhomboidal can be adjusted according to the depth of the rough. However, with its tightly packed facets found both on its crown and pavilion, it is apparent that the Portuguese cut would work better on a larger stone than a small one. This style, though, is less prevalent in the market than the round brilliant.

At the moment of writing, this writer tried to conduct an online research regarding the history and origin of Portuguese cut but, to my surprise, there was nothing to be found. According to my instructor, the name Portuguese cut probably suggests is association with Brazil or South America and that, to his knowledge, this cut would’ve been executed by using the Jam Peg machine. For those of you who are not familiar with faceting machine, jam peg is a wooden device containing a series of holes in which a dop stick (a wooden or metal holder that keeps the gemstone in place during the faceting process) can be fixed at varying angles.

Judging from the fact that, back in the old days, the primary goal of a gem cutter was simply weight retention, the design-led Portuguese cutting style suggests that it could have been a modern invention. With that being said, the writer will keep an eye out and see if I come across anything that changes this assumption, and share my discovery with you readers who are just as curious as I am.

What is it like to facet a Portuguese cut?

The writer has to admit that faceting a Portuguese cut had been an exhausting process as it felt like an never-ending journey. As my avid readers would have known, the level of precision I’m seeking is extremely high and that I demand each facet to be perfectly in line with its neighbouring facet — even a variation as minor as 0.1mm would not have been acceptable.

During the process of faceting the pavilion of a portugese cut

Needless to say, I’ve poured an enormous amount of concentration and energy into the cutting process and, given the number of facets there are, I spent about 13 to 14 hours on my first Portuguese cut — which may well be my last — from rough to polished.

Yet, this exhaustive process does have a silver lining: having already reached the level of complexity involved in faceting a Portuguese has made it a lot more easier for me to carry out the rest that followed since no other fancy cut styles would have this many facets like the Portuguese cut!

Before this ends, may I also remind you that I was utterly satisfied with the outcome of this time-consuming Portuguese cut.