Several museums have “What is it?” exhibits that display unusual items in the hope that someone will recognize a rarely used specialized tool or a pot for an ethnic dish unfamiliar to us today. Recently we saw a 12z-inch-diameter jasperware dish with an 8-inch-high cover sold at auction as a “pancake server.” It looks very much like a 19th-century English dish made to hold a round of stilton cheese. Or it could be a pottery cake dish and cover similar to the plastic cake carrying dishes made today. Research in books and online and conversations with experts have not provided a definitive answer. We are still not sure how the dish was used, but perhaps it was used in several ways. Large ceramic covered cheese dishes that hold a full wheel of cheese are not popular for household use today. But they were produced in the 1800s by many English firms, including Wedgwood, Spode and Minton, as well as Dudson Pottery, which made a large number of cheese dishes. The dishes were called cheese stands in 19th-century ads. The cheese was kept covered on the table to control its strong odor, stave off mold and keep insects away. A pancake server is similar in size and shape, but it has a small hole in the cover to let steam from the stack of hot pancakes escape. A cake might be kept under the cover of a similar dish, but cakes were usually kept on open pedestal- style cake stands. The covered jasperware dish we saw identified as a pancake server auctioned for $153. It’s the same size and shape as a cheese dish.

Q: I have a spoon with a mother-of-pearl bowl and handle and a metal piece connecting them. I would like to know what it was used for and what the approximate value might be.

A: You have a caviar spoon. Caviar spoons are usually made of mother-of-pearl, although you can also find them made of bone, glass and other nonmetallic materials. This is supposed to keep the caviar from picking up a metallic taste. Since caviar is packed in metal cans or in glass jars with metal tops, experts think metal spoons are actually OK (although caviar tarnishes silver). However, if you want to avoid using a metal spoon, a mother-of-pearl caviar spoon is a nice touch. New ones cost about $40.

Q: I have a green ceramic candy jar shaped like the Marshall Field’s clock. Does it have any value?

A: When a Chicagoan says, “Meet me at the clock,” everyone knows which one. The landmark 12-story Marshall Field’s and Co. department store was built in downtown Chicago between 1892 and 1914. The Great Clock was installed on Nov. 26, 1914. Norman Rockwell immortalized the clock when he painted it for the Nov. 3, 1945, cover of the Saturday Evening Post. Your jar was originally sold containing chocolates. It’s worth $100 to $300. Much to the chagrin of the residents of Chicago, Marshall Field’s became “Macy’s on State Street” in 2006.