Dating blob top bottles
Blob Top: thick rounded lip, on most soda and mineral water bottles.
For example, some bottles, especially 19th century to early 20th century soda and beer bottles have a blob-top.Amethyst colored glass: clear glass that has been exposed to the sun or a very bright light for a period of time and has turned a light purple color.Note: Only glass containing manganese will turn purple.Another category easy to identify are the ink bottles.On the other hand, most food and cosmetic jars differ from many other pieces of glass, but it is generally difficult to tell them apart without embossing.Machine made bottles generally have a distinct side mold seam visible on the body, shoulder, and all the way from the neck and may incorporate part of the lip.
Bottles in the period of 1890 to 1910 were made by a combination of techniques ranging from being blown in a mold by hand with the top hand-finished, to machine made bottles that had minor hand finishing of the top.
Pontil and Mark: The pontil is a long rod used to hold a bottle when it is being made in order to give the blower a chance to apply or finish the top.
When finished this pontil is broken off or ground off.
Among hand made bottles, certain techniques for hold and gathering the glass changed over the time.
The most important identifying feature of the antique bottles is the pontil or scar, on the base of the bottle.
[Keep in mind that pontil scars are still found on modern-day artisan made or boutique glassware pieces.] Pontil marks may be open rings or solid disks.