Antique Glass Identification: Types, Marks and Clues

Antique glass identification works best in this order: how the piece was made, then its colour and any glow, then marks and pattern.

• How it was made. Run a finger along the edges of the pattern. Pressed glass is made by forcing molten glass into a mould with a plunger (Wikipedia), so the pattern is soft-edged and you can often find mould seams. Cut glass has sharp, crisp facets cut by hand. Blown pieces may show a pontil mark on the base where the glassmaker's rod was attached (Decorative Collective).
• Colour. Note the exact shade in daylight. Depression glass came in crystal, pink, pale blue, green and amber, with rarer yellow, cobalt, ruby, black, jadeite and delphite (Wikipedia).
• UV glow. A bright green glow under an ultraviolet torch means uranium glass (Wikipedia).
• Iridescence. An oil-slick sheen on pressed glass points to carnival glass, made by applying metallic salts while the glass was hot (Wikipedia).
• Marks and labels. Look on the base and side for a trademark, logo, symbol, signature or paper label (Decorative Collective).
• Pattern. Match the pattern name to a maker and period using a pattern reference.

• Victorian glass, 1840 to 1900. Antique cut glass from this period is expensive and harder to find (Decorative Collective).
• American Brilliant cut glass, from the 1870s. Deep, sharp cutting on heavy lead glass, which the industry misleadingly called crystal; the high lead content made it easier to cut (Wikipedia).
• Early American pressed glass, from the 1820s. Bakewell's 1825 patent was for furniture knobs; full-size presses followed around 1827 at the New England Glass Company (Wikipedia).
• Art glass, 1890s to early 1900s. Tiffany Favrile, Steuben, Durand and Quetzal (Decorative Collective).
• Carnival glass, 1908 to about 1925. Fenton, Northwood, Imperial, Millersburg, Dugan and others in the US; also Sowerby in England and Brockwitz in Germany (Wikipedia).
• Depression glass, 1929 to 1939. Given away in food boxes and at cinemas; more than 100 patterns from over 20 makers, mostly in the Ohio River Valley (Wikipedia).
• Elegant glass, the finer glass of the Depression years, by Cambridge, Fostoria, Heisey and Duncan and Miller (Decorative Collective).
• Kitchen glass, 1920s and 1930s, including Jadeite, Delphite, Fire King and Platonite (Decorative Collective).
• Uranium glass, popular from the 1880s to the 1920s, nicknamed Vaseline glass in the 1930s (Wikipedia).
• Mid-century European glass, such as Murano, Scandinavian and Czech pieces, which the 20th Century Glass encyclopedia catalogues by maker and label.

This is the single most useful distinction, because cut glass is usually worth far more than pressed glass made to imitate it.

• Edges. Cut facets are sharp enough to feel; pressed patterns are rounded.
• Seams. Pressed glass comes from a mould, so look for fine raised lines where mould parts met. Cut glass has none in the cut areas.
• Weight. Cut glass of the Brilliant period was usually heavy lead glass (Wikipedia).
• Pattern regularity. Moulded imitation cut glass reproduces the same pattern exactly; hand cutting varies slightly.

Wikipedia notes that makers of imitation cut glass using moulds had many more rejects because of mould complexity, which is one reason early pressed "cut" patterns can look slightly blurred.

• Signed art glass by makers such as Tiffany, Steuben or Durand is the top of the market (Decorative Collective).
• Rare colours and patterns. Rare Depression glass pieces bring several hundred dollars (Wikipedia), and Decorative Collective names Hazel-Atlas's Royal Lace as the most sought-after Depression pattern. In carnival glass, prices run from a few dollars to thousands; marigold, the most common colour, sells lowest and rare colours highest (Wikipedia).
• Cut glass of the Victorian and Brilliant periods is expensive and harder to find (Decorative Collective).
• Complete sets appraise higher than single pieces (Decorative Collective).
• Condition. Chips, cracks and cloudiness reduce value.

Beware of reproductions: Wikipedia notes that Depression glass reproductions are still being made, and many carnival glass makers never marked their glass, so a lack of marks proves nothing either way.

Wikipedia summarises research finding that most uranium glass is only negligibly radioactive and that its radiation posed no danger to the public or to conservators. Uranium content ranges from traces to about 2% by weight, with some 20th-century pieces up to 25%. If you have concerns about a particular piece, ask your local radiation protection authority rather than relying on a general answer.

You can narrow down most pieces from photos if you take the right ones:

• the whole piece against a plain background;
• the base, straight on, to show any mark, label or pontil;
• a close-up of the pattern edge, to show cut or pressed;
• the piece under a UV torch in a dark room, if you have one.

AntiqLens identifies glass type, pattern and likely maker from photos. Pinterest boards and Ruby Lane's identification boards are useful for browsing patterns, but for dates and makers rely on a reference such as the 20th Century Glass encyclopedia or a pattern book.

Research and drafting for this page were assisted by AI and checked line by line against the sources listed below. Prices are copied from the named auction house, dealer or guide with the sale date where the source gives one and the date we checked it; asking prices and estimates are labelled as such, and where a figure could not be confirmed we say so rather than estimate. If you find an error, tell us and we will correct it.