How to Tell if Glass is Cut

Cut glass is a term used to describe a glass item that has been hand decorated using machine cutting wheels. The artisan cuts follow a specific pattern. Glass cutting can be traced to the ancient Egyptians, and examples can be found throughout the world. American cut glass interests a large number of collectors, particularly the pieces created during the American "Brilliant Period" from 1876 until 1917. Cut glass is still produced today, and copies of the patterns from the Brillant Period make it difficult to detect vintage glass from the new.

Difficulty: Moderate

Instructions

Things You'll Need:

• Glass cleaning cloth
• Cut glass reproduction catalogs (optional)

How to Tell if Glass is Cut

1. Do the weight test. Cut glass, leaded crystal, is dense. Pick up the glass piece. It should seem extremely heavy. Lift other non-cut glass pieces of the same size for a comparison.

2. Do the "ping test" on the glass. Leaded crystal glass is used in cutting due to the softening properties of lead oxide.(Lead oxide allows the glass to be cut without breaking.) Place the glass on a flat surface. With the thumb and forefinger, lightly flick the finger on the glass. If the glass is leaded crystal, a clear ringing sound will be heard. If a dull "thunk" is heard, the glass is not leaded crystal. Move on to the next step, if ringing is heard.

3. Hold the piece to the light. Small rainbows should reflect in the sunlight. The light should bounce light from cut to cut.

4. Look closely at the cuts. Each cut should have a crisp, clear edge. Pressed or molded glass will have a slightly rounded edge.

5. Check for a signature on the bottom of the piece. Cut glass is not always signed, but many manufacturers marked their pieces. American cut glass companies include Libbey, Jewel, Sinclaire, Hoare, Meriden, Hawkes, Tuthill and Dorflinger. Use the link below or purchase a cut glass history book to see the manufacturer's marks that were put on cut glass pieces. Cut glass is also made by design. Take a photo of the piece and compare the design to other identified cut patterns.

Tips & Warnings

• Bring a glass polishing cloth when testing cut glass. Many cut glass pieces look dull if they are dusty. The cleaning cloth will allow the edges to better reflect light.
• If starting a collection of vintage cut glass, make sure to review fraud warnings in books and on the Internet. Many vintage patterns have been replicated, using modern cut glass equipment. Modern cut glass is priced significantly lower than vintage pieces.

Resources

• American Cut Glass Association Website