Bean: Short for jelly bean (see below).

Co-mingled: Co-mingled sea glass is that which quality falls between keepers (see below) and throwbacks (see below). These pieces are legitimate pieces of sea glass, but not pieces that any of us want to save in our personal collection of keepers.

Day-maker: A day-maker is that single keeper (see below) that makes a sea glass outing worthwhile. A day-maker is usually found at the end of the outing and redeems an otherwise bad day. A day that starts with a good piece doesn’t require a day-maker the same way a frustrating day does.

Floater: There are two usages of this term. In both cases, it refers to a piece of sea glass found well exposed; easy to see if looking. I have always used it to describe a piece found in otherwise clear, low-tide beach “floating” on the damp sand. These pieces glow in the sun like jewels. My dad would use the term to refer to a piece lying on top of dry sand well up the beach from the water. In this scenario, clear pieces, especially well frosted/pitted ones, can be hard to spot, even at one’s feet.

Frosting: This is translucence that comes from the abrasion of class and is related to pitting. A piece can be frosted, but not fully smooth, especially where there are new cracks.

Hand: I borrow this term from the fabric world: how a fabric feels in the hand. Sea glass has hand too. A smallish piece may have an overall feeling in the fingertips that gives it a special quality that an other, larger piece might not have. Plate glass pieces do not have much hand. They just don’t feel great to the touch. Conversely, even a small jelly-bean (see below) can have great hand. A small piece of an ancient milk bottle (with a massive rim) is much more likely to have great hand than larger piece of a more modern, light-weight beer bottle.

Jelly bean: This is another term coined by my dad. It describes a piece of sea glass with an ideal, or nearly ideal, shape. Such a piece is fairly symmetrical and evenly smoothed, frosted/pitted. This is gold standard. In our travels we see more pieces with the curve of a bottle (especially parts of bottle tops) that would not qualify as jelly beans. Pieces from thin bottle bottoms and plate glass are not jelly beans, either.

Keeper: From “that’s a keeper!”. We all save our keepers in our own marked mason jars.

Material: Material describes the rocks and pebble fields washed up onto the beach. While some floaters (see above) are not associated with material, many pieces of sea glass are. It appears to me that, not unsurprisingly, the size of sea glass relates to the size of the material – up to a point. While the tiniest pieces come along with pea gravel sized material, glass doesn’t survive in pieces as big as the largest fist-sized rocks. There is, therefore, a size-range of material that contains good sea glass.

Pitting: Pitting is the deep surface wear of glass. From what I have read, pitting is caused by acids in water. Given that acid levels in seawater aren’t high, a deeply pitted piece of glass must be very old – having been immersed for a long time. I have nothing other than other sea glass books to go by, but it seems plausible. I have to imagine that pitting could also be micro-fractures caused by tumbling with rocks.

Ring: A completely enclosed circle of glass from a bottle top. We only have one example of this ourselves, though one can find many pictures and examples (i.e.: North American Sea Glass Association show).

Smoothing: Smoothing is an essential attribute of sea glass. Where a piece might otherwise be old and well frosted/pitted, if it isn’t fully smooth it isn’t a great piece. Lack of smoothing is seen in new pieces and is often seen in large, obviously-old chunks of glass with a recent chip, crack, or break. Lack of smoothing can render an otherwise great piece a throwback.

Throwback: a piece of glass that isn’t worth keeping. The decision to throwback can be made immediately or after evaluating pieces later.

Whale: This is a term coined by my dad. It refers to relatively huge pieces of sea glass. These were often found by him well away from the water in dry sand – see floater above. These pieces were often of sub-standard quality in my opinion. They are likely to still be in the process of breaking into smaller pieces. As such, I would consider most of what he called whales as throwbacks, due to insufficient smoothing (see above).