Lavender Sea Glass
Lavender sea glass is pale and may look white on the beach. The best way to find it is to collect as much white sea glass as you can, while sorting it out you may discover that you have a piece or two!
Lavender sea glass started out as clear colorless glass, much of it comes from early American pattern glass. Manganese was used in the production of clear glass before 1930. The lavender color is a result of the sun interacting with the manganese. This also happens with clear glass made with arsenic before 1940, the sunlight turns this glass a washed out golden yellow. Bottle and glass collectors call this "sun-changed" glass, lavender is sometimes referred to as "sun-purple".
For sea glass collectors sun-purpled sea glass is a treasure. Amongst collecters of antique glass, such as early American pattern glass, it causes havoc. Antiques in mint condition are the most valued and coveted. Antique glass that is sun purpled is not considered "mint", whereas in the seaglass world the deeper the lavender color the better!
Knowledgeable sea glass collectors leave their "sun-changed" sea glass in a sunny spot so that the color will intensify over time. It is the only sea glass I know of that continues to be transformed by the forces of nature after it is removed from the beach.