It doesn’t matter exactly where you are shopping for antiques and collectibles, you will run across a type of glassware called Opalescent glass. What is it exactly?

Opalescent glass is a general term for either a clear or colored glass that has a milky white,opaque or even a translucent effect to a portion of a glass piece.  It could be limited to just the rim of the piece, but you will also see it on the body of the item.

Lalique, Sabino, Jobling (this is from England) and even Fenton are all well known for their opalescent glass production.  This type of glass has also been produced in various other countries like Italy and Czechoslovakia.

One way of creating this glassware is the slow cooling of the thicker areas of the glass.  This results in what’s called crystallization, which is the formation of the milky white layer.  Another method is used in hand blown glass.  When hand blowing the glass, you use two layers of glass—the outer layer will contain chemicals that react to heat to cause the opalescence.

Another way to create Opalescent glass is to reheat certain areas of a piece and apply chemicals to the glass.  When you reheat the piece, the chemicals you use will create the opalescence (the chemicals are heat sensitive).

Over the years, there have been quite a few different colors that have been made that sport this type of effect.  Here are some of the colors that you will run across:

Amber Opalescent

French Opalescent

Pink Opalescent

Blue Opalescent

This is just a few of the colors that have been made.  What colors have you run across?