Lotus Pigeon Blood is the Lotus Gemology laboratory's defined colour grade for ruby that meets the parameters of the historic pigeon blood description: a vivid red of medium-strong saturation, often with a slight purplish bias, set against strong red fluorescence under longwave ultraviolet. The designation is granted only when a stone matches Lotus's published reference window under standardised daylight-equivalent illumination, and is independent of origin and of treatment status.

Structured tiers

The Lotus pigeon blood call is broken into three tiers - PB1, PB2 and PB3 - covering the apex, the middle and the entry point of the category respectively. The structured scale was introduced to limit the dilution of the term and to give the trade vocabulary for distinguishing among pigeon blood stones. Each tier is treated separately in this dictionary.

Acceptance

A Lotus pigeon blood call is one of three or four colour designations that materially move price on a top-grade ruby, alongside the Gübelin and SSEF pigeon blood calls. For the highest-end market, a stone carrying multiple laboratory pigeon blood designations is increasingly the buying convention.