My newest idea is that they are Chinese "export" glass, or "Peking" glass. Anybody knowledgeable in that field care to weigh in? If so, how old are they and how can you distinguish antique (1700s/1800s) from modern (1930s)?
They are thick walled and composed of an opaque mixed olive green (agate?) glass. They measure 5 3/4" tall. An interesting feature is they have a dark circle at rim, which appears to be a manufacturing effect rather than decoration, almost as though the glass were cased. Anyhow, I'm stumped as to age, maker, and region. I'm assuming they are vases and not bottles. Any help would be appreciated.