Royal cut is a trade term applied loosely in the coloured-stone industry to mixed-cut gemstones that combine a brilliant-cut crown with a step-cut pavilion, similar in concept to the radiant cut but without the patented facet arrangement. The name is not standardised across cutters or laboratories; it is descriptive trade vocabulary rather than a defined cutting style. A buyer who encounters a stone described as a royal cut should ask the cutter for a more specific description of the facet structure rather than assume any particular optical signature.

What the term covers

In coloured-stone cutting, a mixed cut combines two faceting strategies: brilliant-style triangular and kite-shaped facets that radiate from the centre of the stone, and step-cut rectangular facets arranged in concentric tiers. The brilliant pattern emphasises light return and scintillation; the step pattern emphasises clean broad colour flashes and is easier on weight retention in deep rough. A royal cut, in this loose sense, takes the brilliant approach on the crown and the step approach on the pavilion, or some hybrid that mixes the two strategies on each side of the girdle.

The radiant cut, patented in 1977 by Henry Grossbard for diamond, is the most precisely defined version of this mixed-cut concept and uses 70 facets in a specified arrangement. Coloured-stone cutters working with sapphire, tourmaline, garnet, and other species often produce stones with a similar visual character but without the patented facet count or proportions. Royal cut is one of the names that has attached itself to such work; radiant-style, modified radiant, and brilliant-step mixed cut are also used.

Why cutters use it

The choice of a royal-cut style is most often driven by the proportions of the rough rather than by market demand for a specific named cut. A piece of rough sapphire or tourmaline with awkward depth, intermediate length-to-width ratio, or asymmetric inclusions may not yield a fine emerald cut, oval, or cushion at acceptable weight retention. A mixed cut with a brilliant crown allows the cutter to maximise face-up brilliance while a step pavilion captures more of the depth than a brilliant pavilion would. The result is a stone that performs adequately face up, retains close to the maximum recoverable weight, and avoids the windowing common in shallow brilliant pavilions.

For the buyer, the trade-off is that no two royal-cut stones are quite alike. Without a defined facet arrangement, the cut's optical performance depends entirely on the individual cutter's judgement and the rough's geometry. A well-executed royal cut can rival a fine radiant in face-up appearance; a poorly executed one can show extinction or windowing that a more disciplined cut would have avoided.

In the market

Royal-cut stones are most common in the medium and lower commercial tiers of the coloured-stone market, where weight retention is a significant pricing variable. Higher-end material is more often given a recognised cut — emerald, oval, cushion, radiant — that buyers can specify and benchmark. The looseness of the term means that royal cut on a memo or invoice carries no specific assurance about facet count or proportions; the stone itself must be evaluated visually and dimensionally.

The term should not be confused with any of the proprietary diamond cuts that incorporate the word royal, such as the Royal Asscher cut, which is a defined and trademarked diamond design. The coloured-stone trade's use of royal cut is unrelated.

Identification and evaluation

When evaluating a stone described as a royal cut, the relevant questions are the same as for any coloured-stone purchase: face-up colour and brilliance, presence or absence of windowing or extinction, symmetry of the outline, polish quality, and the weight-to-spread ratio. The mixed-cut nomenclature does not change the assessment; it only signals that the cutter has used a hybrid faceting strategy and that the buyer should look at the stone rather than the name.

Further reading

• GIA Gems & Gemology — articles on coloured-stone cutting and mixed-cut design
• International Gem Society — radiant and mixed-cut reference
• Gem-A — Journal of Gemmology cutting and faceting articles