PB1 — The Top Tier of the Trade's Pigeon-Blood Ruby Range
PB1 — The Top Tier of the Trade's Pigeon-Blood Ruby Range
Dealer shorthand for the most saturated, fluorescent, unzoned reds within the pigeon-blood band
PB1 is informal trade shorthand for the finest tier within the pigeon-blood colour range in ruby — the most saturated, purest red with strong fluorescence, minimal colour zoning, and minimal modifier. The designation is not a laboratory grade. It is dealer language used in Bangkok, Hong Kong, Yangon, and the Asian wholesale trade to stratify the small population of stones that meet pigeon-blood criteria into commercially distinguishable tiers. PB1 sits above PB2 and PB3 in the same informal scale and below the categorical pigeon-blood comment that the Asian and European laboratories will issue on a qualifying laboratory report.
What PB1 designates
The pigeon-blood designation as used by Gübelin Gem Lab, SSEF, Lotus Gemology, and AGL refers to a specific combination of hue (vivid red with no modifier or with a faint pink modifier), tone (medium to medium-dark), saturation (vivid), and fluorescence (strong red under long-wave ultraviolet and under daylight, contributing to the stone's living glow). PB1 narrows that band to its top end: stones whose colour reading places them at the saturated, fluorescent, eye-clean centre of the pigeon-blood territory rather than at its margins. Trade practice treats PB1 stones as candidates for laboratory certification with a pigeon-blood comment and prices them accordingly — typically at multiples of comparable pigeon-blood-grade stones rated PB2 or PB3.
Origin matters within the PB1 tier. The classical pigeon-blood reference standard is the Mogok ruby of upper Burma, and PB1 stones of confirmed Burmese origin command the highest prices in the market. Mong Hsu rubies in their best, untreated examples can also reach PB1 territory but trade at a discount to Mogok. Mozambique rubies from Montepuez produce occasional PB1 examples; the trade has become more comfortable with Mozambique pigeon-blood designations over the past decade as laboratories have built sufficient analytical reference material.
Heat treatment and PB1
Heat treatment reduces but does not eliminate eligibility for PB1 designation. Many laboratory pigeon-blood comments are issued on heated stones, and the trade applies PB1 to heated as well as unheated material, with a strong premium for unheated. Buyers should expect any PB1 designation to be accompanied by a treatment statement: unheated, heated only, or heated with low-residue confirmation by the issuing laboratory.
Limitations of the term
The term PB1 has no formal definition. Its use varies between dealers, and its boundaries are negotiated stone by stone. Buyers should treat PB1 as a marketing shorthand and rely on the laboratory report's colour comment, fluorescence note, and treatment determination as the load-bearing documentation. Where a stone is offered as PB1 without a laboratory pigeon-blood comment, the buyer should question whether the stone would in fact qualify under the laboratory's standard.