Base of the Bottle Markings In most cases, one- or two-digit numbers are actually mold numbers that indicate the specific bottle mold or section in an automatic bottle machine. Base numbers also indicate bottle styles or shapes, manufacturing dates, or factory location codes.

What is the rarest piece of depression glass?

Pink glass is most valuable, followed by blue and green. Rare colors such as tangerine and lavender are also worth more than common colors like yellow and amber. If you stumble upon an extremely rare piece like the red ruby Aladdin Beehive Lamp, expect to pay $800 or more!

How can I tell if glass is blown?

Look at the Lip and Base. Check the lip of the vase for a pinched area. A small pinched area around the lip of a vase indicates the spot where blown glass is removed from the blowing tube. Finding a pinched area at the lip or opening of the vase is a good indicator of blown glass.