Are lidded vases usually sold in pairs?

Pairs are very common. "Pair" appears in well over a third of titles, and plural "vases" at the same rate, so a single vase and a facing pair are both ordinary sights. Sets of three or five turn up as well, described as garnitures. They are the exception rather than the pattern, and they reach the highest end of the range.

What does pot pourri vase mean?

It's a covered vase whose lid is pierced so scent can escape. The phrase appears in a run of titles, most often within the Royal Worcester group. Otherwise it behaves like any other vase and cover, and dealers list it under the same heading.

How old are most of these?

The dated field spans 1800 to 1960. "19th Century" is by far the biggest bucket, which places a piece in a hundred-year span and no closer. Decade buckets are thinner, with the 1900s the largest of them. Eight listings are dated 18th century, and a 17th-century Arita pair and a circa-1680 pair sit outside the main span altogether.

Which countries do they come from?

Japan supplies the largest share, roughly a third, through Imari, Satsuma, Kutani, Arita and Fukagawa. English factory pieces follow at about a fifth, and French Sèvres-style vases at roughly one in ten. Smaller groups cover Dutch Delft and continental faience and maiolica, Germanic and Viennese porcelain, and Chinese porcelain, cloisonné and champlevé.

Are they always porcelain?

Almost always ceramic, whether porcelain, faience, maiolica or crackle-glazed earthenware. A few sit outside that. The archive holds a pair of ivory-mounted burr fruitwood urns of campana form, a Bohemian cabochon overlay glass example, and a pair of Japanese mixed-metal vases.

How many come up for sale each year?

Around 28 lidded vases are listed a year on Sellingantiques. Fifty-eight different dealers have handled one, so no single specialist owns the field, and no maker reaches enough listings to count as a category-wide presence.