Collectors
How ShellBidder grades specimen condition, from GEM to F, following established shell-collector conventions.
Shell condition is an important part of specimen value. At ShellBidder, grades are based on the overall preservation, completeness, surface quality and visual appeal of each specimen.
Natural growth marks, healed injuries and species-specific characteristics are not automatically considered defects. Any significant chips, repairs, erosion or other condition issues should be disclosed separately in the listing description and photographs.
An exceptional specimen in virtually flawless condition.
GEM is reserved for truly exceptional specimens.
A superior collector-quality specimen with only extremely minor imperfections.
An excellent specimen suitable for advanced collections.
A high-quality specimen showing minor defects or normal natural wear.
A strong collector-grade specimen.
A good collectible specimen with noticeable but limited imperfections.
Suitable for general and reference collections.
A collectible specimen with obvious condition issues.
Often suitable for study, reference collections or collectors seeking uncommon species at a lower price.
Condition grades are guidelines, not absolute standards.
Grading can vary slightly between collectors, dealers and species. Some shells are naturally fragile, commonly eroded or rarely found in perfect condition.
“The photographs and individual condition notes are always part of the specimen description and should be considered together with the assigned grade.”