Such fine knobs were used in mansions at the entrances to formal areas, such as parlors and dining rooms, where homeowners entertained guests.
Today, hardware-store-variety glass knobs cost as little as a pair, but the materials and craftsmanship are far inferior to the vintage counterparts.
The larger the slice, the better odds of finding that particular color.
Keep in mind that though these are the main colors of sea glass, each color can vary slightly in its shade from light to dark. Many shards, says Richard La Motte author of , can be dated back to late 1800s and and early 1900s.
Before long, developers were outfitting doors in suburban ranch houses with utilitarian-looking steel orbs. But there are important points about fit, style, and construction to consider before buying.
If you are looking to replace a single knob in a set, always bring along the mate, since there are more than 100 glass-knob patterns to choose from. Doorknobs manufactured after 1900 have threads inside their shanks that fit square, threaded spindles.
Glass doorknobs date back to 1826, when the process for pressing molten glass into molds was invented, but they didn't become ubiquitous until after the United States entered World War I, in 1917.
Cast brass, bronze, and iron doorknobs, which had dominated the hardware market since the beginning of the Victorian era in 1860, were in short supply because metals were needed for airplanes and ammunition.
Glass knobs made before the turn of the century were typically mounted on unthreaded spindles with holes in either end.
In both cases, the knobs are secured to the rods with small setscrews.
"The old glass has a watery look and refracts light differently," says Kittle of knobs gently worn by time and use.