How to Identify Pottery & Ceramics: Marks, Glazes, and Value

Underside of a ceramic vase showing a painted maker's mark on the base

By Charles Rose, founder of Glacier Art Objects

To identify pottery and ceramics, start with the body: earthenware is porous and gives a dull thud when tapped; stoneware is dense and rings; porcelain is translucent when thin and rings with a high, clear note. Then read the maker's mark on the base — but never authenticate by the mark alone, since marks are easily faked. The body, glaze, decoration quality, and signs of age tell you far more.

Ceramics is the oldest art form humans still practice. Every major civilization produced its own tradition, and each is collectible in its own right. Here is the foundation every collector should have.

Table of contents

Earthenware vs. stoneware vs. porcelain

Three categories cover almost everything:

Earthenware is fired at low temperatures and is porous unless glazed. Common in folk pottery, tin-glazed wares (delft, faience, maiolica), and most studio pottery. Gives a dull thud when tapped.

Stoneware is fired hotter, dense and non-porous. Includes salt-glazed German wares, Yixing teapots, and most contemporary studio work. Rings when tapped.

Porcelain is fired hottest from a white kaolin body, translucent when thin. Invented in China around the 7th century; Europe didn't crack the formula until 1708 at Meissen. Rings with a high, clear, sustained note.

The tap test is a useful first filter — but note that a crack will dull the sound on any body, which is itself a handy condition check.

How to read a maker's mark

Most ceramics from the 18th century onward carry a maker's mark — symbols, letters, numbers, or impressions on the base identifying the factory, period, and sometimes the artist. Three principles:

  1. Marks don't authenticate by themselves. Forging a Meissen crossed-swords mark is easy; forging the body, glaze, and decoration to match is hard. The mark must be consistent with everything else.
  2. Marks date pieces only within ranges. Factories used the same mark for decades, often with subtle variations indicating the period.
  3. Reference works exist for almost everything. Kovels, Cushion's Pocket Book of Marks, and online databases like Kovels.com and Gotheborg.com (for Chinese porcelain) are the place to confirm a mark.

For Chinese reign marks specifically, see our guide to identifying Chinese porcelain marks.

Understanding glazes

The glaze is where ceramic artists most clearly distinguish themselves. Common categories include tin-glazed earthenware (the white "canvas" of delft, faience, and maiolica), salt-glazed stoneware (with its distinctive "orange peel" texture), celadon (green to grey-green, prized in Chinese and Korean work), copper-red and sang-de-boeuf glazes (difficult to fire, highly prized), and crystalline and ash glazes (popular in art pottery and studio work). A great glaze rewards close looking — even but not lifeless, with a surface depth that's impossible to photograph adequately.

How to check condition and spot restoration

Ceramics show damage clearly if you know how to look:

  • Hold to a strong light. Cracks and hairlines show as dark lines, especially in porcelain.
  • Tap test. A clear ring suggests sound structure; a dull thud often means a crack.
  • Check the extremities first. Rims, handles, spouts, and fingers are where damage and restoration concentrate.
  • Use a UV (black) light. Many restoration materials — fills, overpaint, adhesive — fluoresce differently from original glaze and glow distinctively under UV. Originals usually don't.
  • Run a fingernail across suspect areas. Hidden cracks often have a tactile edge invisible to the eye.

Damage is part of ceramics — few 18th-century pieces survive unmarked. The question is honest disclosure. Restoration is acceptable when disclosed; concealed restoration is fraud.

What makes ceramics valuable

Value comes from the maker and period (a peak-period piece from a great factory commands a multiple of lesser work), quality within that maker's output, form and design, condition (a hairline can cut value 30–60%), decoration quality (hand-painted beats transfer-printed; a named painter adds value), rarity, and provenance. Major European factories worth learning include Meissen, Sèvres, Worcester, Derby, Wedgwood, and Royal Copenhagen; American art pottery (Rookwood, Grueby, Newcomb College, Roseville) is a very active field; and 20th-century studio potters (Leach, Hamada, Lucie Rie, Hans Coper) are now firmly established in the art market.

Frequently asked questions

How do you identify pottery and ceramics?

Start with the body: earthenware is porous and gives a dull thud, stoneware is dense and rings, and porcelain is translucent when thin and rings with a high clear note. Then read the maker's mark on the base, but confirm it against the body, glaze, decoration, and signs of age rather than relying on the mark alone.

What is the difference between earthenware, stoneware, and porcelain?

They differ by firing temperature and clay body. Earthenware is fired low and is porous; stoneware is fired hotter and is dense and non-porous; porcelain is fired hottest from a white kaolin body and is translucent when thin. Each produces a distinct sound when tapped.

How do I read a maker's mark on pottery?

A maker's mark on the base identifies the factory, period, and sometimes the artist. Compare it against reference guides such as Kovels or Cushion's Pocket Book of Marks, or online databases. A mark only dates a piece within a range and does not authenticate it on its own, since marks are easily faked.

How can you tell if ceramics have been repaired?

Hold the piece to strong light to reveal cracks, tap it to listen for a dull thud, and check rims, handles, and spouts where damage concentrates. A UV (black) light is the most reliable home tool: most restoration fills and overpaint fluoresce differently from original glaze, while originals usually do not.

What makes a piece of pottery valuable?

Value depends on the maker and period, quality within that maker's output, form and design, condition (a hairline crack can reduce value 30 to 60 percent), decoration quality, rarity, and provenance. Hand-painted decoration and a named painter add value, while concealed restoration sharply reduces it.

Charles Rose is the founder of Glacier Art Objects and Sand and Rose LLC. Over more than a decade in the trade, he has handled and sold over 18,000 works of fine art, antiques, jade, sculpture, and collectible objects.

Browse our Pottery & Ceramics collection. Each piece includes our best identification of maker and period, with detailed condition notes and references where available.