How can you tell how old sea glass is?
Verdict summary
Older sea glass tends to be thicker, more heavily frosted and pitted, and in colours that are rare today. Clues from the original bottle, such as embossed lettering, the lip finish and mould seams, date it more reliably than the frosting alone.
Rare colours include red, orange, yellow and some blues and purples; common colours are white, brown and green. Frosting depends on the beach as well as on age.
Mudlarkers and beachcombers date bottle fragments from bottle-making features, such as hand-applied lips on older bottles.
Sources: Bottle and glass dating references.
Can you metal detect on the beach? Usually yes: most public beaches allow metal detecting, and beaches are among the best places to find lost jewellery and coins. Some beaches are off-limits, including those in national parks and seashores and in some state parks, and some areas restrict digging in dunes or protected habitat.
How do I know if my find is worth anything? Identify it first: value depends on exactly what it is, its date, condition and rarity. Gold and silver items are worth at least their metal content. For coins and jewellery a reputable dealer or auction house can value them; archaeological finds can be recorded by a museum or finds liaison officer.
Primary sources cited
- Bottle and glass dating references