In the wholesale trade in cultured pearls, B grade is a quality designation indicating pearls that carry visible surface blemishes or moderate lustre, placing them one tier below A-grade material in the most widely used commercial grading scales. B-grade pearls are a staple of volume jewellery manufacturing, where price accessibility takes precedence over near-flawless surface quality. The designation is not standardised across all markets or suppliers, but it is broadly understood within the trade as representing pearls with imperfections covering roughly up to 25 per cent of the surface, or with lustre that is noticeably reduced relative to higher grades.

The Absence of a Universal Standard

No single international authority governs pearl grading in the way that, for example, the GIA's diamond grading system has achieved near-universal adoption for faceted stones. The Cultured Pearl Association of America (CPAA) has published grading guidelines that include lettered tiers — AAA, AA, A, and B — and these are widely referenced in North American wholesale and retail contexts. However, Japanese trading houses, Tahitian pearl exporters operating under French Polynesian regulations, and Australian South Sea pearl producers each employ their own nomenclature and criteria, which may or may not map cleanly onto the CPAA framework. A pearl described as B grade by one supplier may correspond to a different quality level with another. Buyers are therefore advised to examine grading certificates alongside the pearls themselves, rather than relying on grade designations in isolation.

Surface Quality and Lustre Criteria

Within systems that use the B designation, grading is assessed visually under controlled, diffuse lighting — typically a daylight-equivalent source — with the pearl rotated to expose the full surface. Two principal criteria govern the B classification:

• Surface blemishes: Imperfections such as pits, scratches, welts, calcite deposits, or irregular growth rings that are clearly visible to the naked eye. In most CPAA-aligned systems, blemishes covering up to approximately 25 per cent of the surface are consistent with B grade, provided they do not compromise the structural integrity of the nacre.
• Lustre: B-grade pearls may exhibit moderate lustre — reflections of surrounding objects are visible but soft or indistinct, lacking the sharp, mirror-like quality associated with AA or AAA material. Some grading systems assign B grade primarily on lustre grounds even when surface coverage of blemishes is relatively low.

It is worth noting that lustre and surface quality are assessed independently in rigorous grading, and a pearl may qualify as B grade on either criterion alone. The two factors together determine the overall commercial value.

Position Within the Grading Hierarchy

In the CPAA-influenced system, the hierarchy from finest to lowest commercial grade typically runs: AAA — AA — A — B. Some suppliers extend the scale downward with a C grade or an ungraded category for material with very heavy blemishing or very low lustre. B grade therefore occupies the lowest tier of material that is routinely offered in finished jewellery; heavily blemished material below this threshold is generally sold for industrial use, craft applications, or as loose novelty beads rather than set into jewellery intended for retail sale.

Treatment Status

The B-grade designation carries no implication regarding treatment. B-grade pearls may be untreated, or they may have undergone bleaching, dyeing, coating, or polishing — treatments that are common across all quality tiers of cultured pearls. Bleaching to even skin tone and polishing with abrasive compounds are near-universal in commercial production; dyeing and surface coating are more selectively applied. Buyers seeking assurance on treatment status should request disclosure from the supplier or, for higher-value lots, a laboratory report from a recognised gemmological laboratory such as the GIA Pearl Laboratory or the SSEF in Basel.

Pricing and Market Context

B-grade pearls are typically priced at a substantial discount to A-grade equivalents of the same species, size, shape, and body colour. Discounts of 30 to 50 per cent relative to A-grade material are commonly cited in the trade, though the actual differential varies with pearl type. For Akoya pearls — where surface perfection and high lustre are the primary value drivers — the discount for B-grade material can be steep, as lustre and surface quality are the defining commercial attributes of the Akoya category. For freshwater pearls, where surface blemishes are more widely tolerated by the market and where price points are already lower, the differential between A and B grade may be proportionally smaller in absolute terms.

B-grade material finds its primary market in commercial jewellery — mass-market strands, fashion accessories, and promotional pieces — where the price point is the dominant purchasing criterion. It is also used in jewellery designs where the pearl is partially obscured by a setting, or where a deliberately rustic or organic aesthetic is sought. In such contexts, surface irregularities may be considered acceptable or even desirable.

Subjectivity and Buyer Due Diligence

Because pearl grading remains a visual, subjective assessment — even when conducted by experienced graders under standardised conditions — the B designation should be treated as a general guide rather than a precise specification. Two lots both described as B grade may differ considerably in the character and distribution of their blemishes, in the warmth or coolness of their body colour, and in the degree to which imperfections are concentrated on the drill-hole area (where they are less visible in a finished strand) versus the face of the pearl. Experienced buyers examine B-grade lots with particular care, since the range of quality within the designation is wider than in higher grades, and the opportunity to select well within the tier can yield meaningful value.

Further Reading

• GIA: Pearl Quality Factors
• American Gem Trade Association (AGTA)