In the early 1800s, British potters experimented with making an inexpensive, porcelain-like dinnerware that could be mass-marketed. Though often referred to as “semi-porcelain,” ironstone is refined earthenware and not true porcelain. Ironstone dinnerware quickly became popular in Great Britain and even more popular in the United States. By the late 1800s, many American ironstone potteries had formed and thrived.
One of the great pottery-producing areas in the world, and the original producers of ironstone, is the Staffordshire district in Great Britain. Staffordshire potters sought to improve upon the dinnerware commonly called pearlware. This resulted in an earthenware that is harder than pearlware and can be glazed bright white. Charles James Mason first patented the term “ironstone” in 1813, and by the 1820s, many Staffordshire potters were producing the ware. Although early ironstone contained transfer-printed and hand-painted decoration, the potteries discovered that by the 1840s, most consumers preferred plain white dinnerware.
By 1910, the Staffordshire district took on the name Stoke-On-Trent, where dozens of potteries still exist today. The district had two great advantages: abundant clay sources and a nearby seaport. The British potteries limited their ironstone production to dinnerware, and America quickly became their largest market.
Before the advent of ironstone dinnerware, the United States had a limited pottery industry. Its potteries largely produced bricks, tiles, redware and stoneware. The preference for plain white dinnerware in the mid-1800s enabled a fledgling industry to develop, since American potters did not need to be adept at decoration (particularly transfer-printing). Regions in New Jersey and Ohio (and later New York) that had high-quality clay sources and well-developed transportation networks became the centers of American ironstone dinnerware production.
Several large potteries in the Trenton, New Jersey, area produced large amounts of ironstone dinnerware. Production began in the Trenton District in the late 1850s, when potteries began marketing their ironstone dinnerware as ironstone china, white granite, stone china, vitrified china, hotel china and other names. By the 1890s, dozens of potteries had been established to form a thriving industry.
East Liverpool, Ohio, became another major pottery producer. Although it began in the 1840s by producing yellowware, the area around East Liverpool blossomed into a pottery district producing ironstone dinnerware. The ironstone era in Ohio began in the 1870s, when the huge potteries of Knowles, Taylor & Knowles began operation. The Homer Laughlin China Company started production in 1907.
Ironstone dinnerware is thicker and heavier than porcelain. It is easy to identify by its maker's mark. Maker’s marks are typically found in the center of a dish's base in underglaze black, brown, dark blue or other colors. Early American marks are similar in design to English marks, so research might be needed to determine where the plate came from. There are several guides available to help identify and date maker’s marks. It is also important to note that ironstone is a catch-all term for dinnerware that goes by several different names such as semi-porcelain, stone china, white granite, hotel ware and others.