TL;DR: The single cut is a simplified 17 or 18-facet diamond, historically used for very small accent stones. The portrait cut is a genuinely rare, deliberately thin, flat-faceted diamond originally cut to sit over a miniature portrait or lock of hair without obscuring it. Both are historical curiosities more than practical modern choices, occasionally sought after specifically for their rarity and story.
The Single Cut
A single cut diamond has just 17 or 18 facets, compared to the 57 or 58 of a modern round brilliant. It was the standard cut for very small diamonds — particularly melee used in antique pavé and cluster settings — before faceting technology made a full brilliant cut practical at very small sizes. Single cuts have noticeably less sparkle than a modern brilliant of the same size, since fewer facets mean less light dispersion, but they carry genuine antique character precisely because of this simplicity.
Single cuts are occasionally sought after specifically for restoring or matching genuinely antique pieces, where a modern brilliant-cut melee would look visibly anachronistic against the original stones.
The Portrait Cut
The portrait cut is a genuinely rare historical diamond style — cut deliberately thin and flat, almost like a pane of glass, so that the stone could be placed directly over a miniature painted portrait or a lock of hair without obscuring what lay beneath. Popular in mourning jewellery and sentimental pieces from the 17th and 18th centuries, portrait cuts sacrifice virtually all conventional brilliance for this specific, deliberate transparency.
Genuine antique portrait cut diamonds are rare and specialist — they turn up occasionally in estate jewellery and specialist auctions rather than being something a jeweller cuts to order today. Their appeal is almost entirely historical and sentimental rather than about how the stone performs optically.
Why These Cuts Matter Even Though They're Rarely Chosen Today
Neither the single cut nor the portrait cut is a practical choice for a modern engagement ring centre stone — both sacrifice brilliance for historical specificity. Their real relevance is for restoration work, matching antique pieces, or for buyers specifically drawn to owning something with genuine historical rarity rather than optical performance.
Sourcing Antique-Cut Stones at À Vie Diamonds
Get in touch if you're restoring an antique piece or have a specific interest in sourcing a genuinely rare historical cut — this is specialist sourcing work we're happy to discuss honestly, including realistic timelines and availability.
Related Reading
Frequently Asked Questions
What is a single cut diamond? A simplified diamond with 17 or 18 facets, historically used for small accent stones before modern brilliant-cutting became practical at small sizes. It has noticeably less sparkle than a modern brilliant.
What is a portrait cut diamond? A genuinely rare, deliberately thin, flat-faceted diamond originally cut to sit transparently over a miniature portrait or keepsake without obscuring it, popular in 17th and 18th century sentimental jewellery.
Last reviewed: July 2026 · À Vie Diamonds