Macles — The Diamond Trade's Sorting Category for Twinned Triangular Rough
Macles — The Diamond Trade's Sorting Category for Twinned Triangular Rough
How rough-diamond classification handles the flat triangular crystal that won't yield a brilliant
Macles is the trade-language plural of macle, used as a sorting category in the rough-diamond trade for flat, triangular twinned diamond crystals that fall outside the conventional sawable, makable, and near-gem rough classifications. The category exists because macles' flat plate-like morphology — produced by twinning on the octahedral crystallographic plane — does not yield economically as conventional brilliant cuts and requires specialist cutting strategies including rose cuts, portrait cuts, and various contemporary fancy cuts. Macles are priced and traded as a distinct rough category, generally at a discount to comparable-weight equant rough.
Position in the rough sorting hierarchy
Rough-diamond sorting in the traditional De Beers system and its successor sorting frameworks distinguishes a long sequence of categories based on shape, size, colour, clarity, and intended cutting strategy. The principal shape-based categories include sawables (octahedral and dodecahedral crystals suitable for sawing into multiple stones), makables (single-stone production crystals of various single-cut shapes), cleavages (irregular crystals with usable single-stone potential), macles (the flat twinned triangles), and various sub-categories for specific cutting plans.
Within each shape category, further sorting separates by size (typically expressed in screen sizes from less than 0.005 carats up to large special stones), by colour (Cape series for yellow tints, brown series for brown tints, and various other categories), and by clarity. The full sorting matrix can run to hundreds of distinct sub-categories, each with its own pricing and trading characteristics.
The macle category exists within this matrix because the cutting yield from macles is sufficiently different from yield from equant rough that pooling them with other categories would distort price discovery. Macle rough is bought specifically by cutters and cutting houses with the capability to handle the flat morphology efficiently — through sawing into smaller pieces, through rose-cut production, or through specialist fancy-cut work.
Pricing and trade
Macles trade at a discount to equivalent-weight equant rough because of the lower cutting yield and the specialist cutting requirements. The discount varies depending on quality, size, and the strength of demand for the cuts that macles support. In periods when the salt-and-pepper rose cut and contemporary fancy-cut markets are active, macle prices firm relative to equant rough; in periods when those niche markets are softer, the discount widens.
Within the macle category itself, larger and cleaner stones command higher per-carat prices, as in any rough category. A clean white macle of 5 carats may yield two or three saleable rose-cut or portrait-cut stones in attractive sizes, while a small or heavily included macle yields proportionately less and trades closer to industrial-quality pricing.
The buyer base
The buyers for macle rough are concentrated among cutting houses with established capability in non-brilliant cuts. Indian cutting centres in Surat and Mumbai have historically handled significant macle volumes, particularly for rose-cut production targeting the bridal jewellery market and for export to American and European fashion-jewellery brands. Antwerp and Tel Aviv cutters with specialist niches handle the higher-value macle production, particularly for portrait cuts and other window-cut styles.
The contemporary salt-and-pepper rose cut market — which uses macle rough that includes significant black or coloured included material to produce visually distinctive cuts for the engagement-ring and fashion-jewellery markets — has been a growth area over the past decade. Brands including Catbird, Ana Katarina, and a long list of independent designers source macle rough specifically for this style, supporting demand for material that would otherwise have been industrial-grade.
In the trade
For trade users not directly involved in rough buying or cutting, the macles category is most relevant as context for understanding why certain finished diamond cuts exist and behave as they do in the market. The persistence and contemporary revival of rose cut and portrait cut diamonds is driven by the availability of macle rough and the cutting economics specific to this morphology. The relatively narrow market for these cuts compared to brilliant-cut diamonds reflects both consumer preference and the upstream supply constraint imposed by the proportion of mine production that arrives as macle.