[Alice Sun]

Hello, everyone. I'm Alice.

I'm a newbie and I hope you can help me.

What's exactly the differences between ceramic, porcelain, and stoneware? I searched it on the internet, but still couldn't have a clear understanding about it.

Please help me.

Thank you very much.

[Nancy S.]

Alice Sun, on 16 December 2012 - 08:14 PM, said:

What's exactly the differences between ceramic, porcelain, and stoneware? I searched it on the internet, but still couldn't have a clear understanding about it.

Alice,

I'm kinda new at this myself, so here's how I understand things -- and if I'm wrong, I'm sure someone here will let me know.

"Ceramics" is a general term that covers anything made by forming and firing clay. There are industrial applications as well as artistic ones for ceramics, from bathroom tiles, toilets, and sinks to kitchen knives to pieces of the space shuttle.

"Stoneware" is a broad term for most mid-fire clays (cone 4-6) that aren't porcelain. Earthenware, by contrast, is low-fire clay (cone 04-cone 3).

"Porcelain" is a specific type of clay, and I confess I don't know a lot about it other than that can be either mid-range (around ^6) which isn't a "true" porcelain, or high-fire (cone 10-14).

[Lucille Oka]

Nancy S., on 16 December 2012 - 06:07 PM, said:

Alice Sun, on 16 December 2012 - 08:14 PM, said:

What's exactly the differences between ceramic, porcelain, and stoneware? I searched it on the internet, but still couldn't have a clear understanding about it.

Alice,

I'm kinda new at this myself, so here's how I understand things -- and if I'm wrong, I'm sure someone here will let me know.

"Ceramics" is a general term that covers anything made by forming and firing clay. There are industrial applications as well as artistic ones for ceramics, from bathroom tiles, toilets, and sinks to kitchen knives to pieces of the space shuttle.

"Stoneware" is a broad term for most mid-fire clays (cone 4-6) that aren't porcelain. Earthenware, by contrast, is low-fire clay (cone 04-cone 3).

"Porcelain" is a specific type of clay, and I confess I don't know a lot about it other than that can be either mid-range (around ^6) which isn't a "true" porcelain, or high-fire (cone 10-14).

Bravo, very good answers.
Mid-range porcelain is historically called 'soft paste' porcelain, cone 10 and higher 'hard paste'.

[JBaymore]

The field of ceramics includes the technological manipulation of aluminosilicate minerals of all sorts. Many industrial "clay" bodies contain no actual clay as most potters here would know it. But once fired, the work is "ceramic". If it contains silica and alumina minerals, and is affecterd by heat treating the material ... it is "ceramic". Technically... glass is ceramic. Silicon wafers for electronics computer chips are ceramic technology. Ceramic knives and engine blocks are "ceramic" but no plastic clay was involved in their manufacture.

best,

...............john

[Pres]

Nancy S., on 16 December 2012 - 09:07 PM, said:

Alice Sun, on 16 December 2012 - 08:14 PM, said:

What's exactly the differences between ceramic, porcelain, and stoneware? I searched it on the internet, but still couldn't have a clear understanding about it.

Alice,

I'm kinda new at this myself, so here's how I understand things -- and if I'm wrong, I'm sure someone here will let me know.

"Ceramics" is a general term that covers anything made by forming and firing clay. There are industrial applications as well as artistic ones for ceramics, from bathroom tiles, toilets, and sinks to kitchen knives to pieces of the space shuttle.

"Stoneware" is a broad term for most mid-fire clays (cone 4-6) that aren't porcelain. Earthenware, by contrast, is low-fire clay (cone 04-cone 3).

"Porcelain" is a specific type of clay, and I confess I don't know a lot about it other than that can be either mid-range (around ^6) which isn't a "true" porcelain, or high-fire (cone 10-14).

The way I put it to the kids, anything under 2000F. is Earthenware, over 2000F is stoneware and porcelain. Porcelain being a clay body made up of more pure materials closer to silica in content and very little impurities. Usually starting around 2200F going up to 2800F. This for the simplest of explanations for the beginners.

[pricklypotter]

I don't think ^6 porcelains are strictly soft paste anymore. They probably just use a lot of Neph Sy as flux instead of a little feldspar. I thought that strictly speaking soft paste is fritted. ??? if you define it by firing range then ^6 porcelains are soft paste but that would be a tautology.

i think a good definition of porcelain is that it's white, translucent where thin unless glazed with an opaque glaze, rings when tapped, and is completely or almost completely vitrified (less than 1% or .5% or...). In terms of composition some people like to say that it contains feldspars, primary clays (kaolins) and silica, and no ball clay, but a lot of commercial porcelains do contain some ball clay. some of them are not translucent where thin. it's a hornets' nest

stoneware usually contains some iron, and so is grey, buff, red, brown... but white/porcelaineous stoneware contains little iron. i think by stoneware people generally do mean a clay which is at least mid fired (cone 5 and higher?), but can be up to cone 10, that is not completely vitreous when mature (1% - 3%?) and that contains larger amounts of secondary clays. the border between white stoneware and porcelain can be a bit contentious.

[yedrow]

To me, outside of industrial use, ceramic refers to a clay (Al2O3 2SiO2 2H2O) where all of the water has been removed (Al2O3 2SiO2), as John said, an alumino-silicate.

Stoneware refers to a clay-glaze relationship, in a manner of speaking. When we say "stoneware" we are talking as much about the glaze as we are about the clay. I'm not sure that stoneware can be very well defined as a clay(body) by itself based on a unified set of qualities.

Porcelain, again, in a manner of speaking, is a pure clay that developed from work in stoneware. I suspect the Chinese developed porcelain more out of a search for whiteness than anything. It just so happens that to get white you also get refractory. Porcelain is more like glass (vitreous) than the other clays.

Naturally definitions develop from general assumptions into specific observations and then from specific into general categories so some definitions come before the 'specific' part, and some after, leaving opportunities for confusion.

Joel.

[Marcia Selsor]

Joel,

I would wonder about how Salt-glazed stoneware as in German traditions and Early American traditions would fit into your definition of clay-glaze. Granted the glaze IS the clay in that situation.

Marcia

[OffCenter]

Nancy S., on 16 December 2012 - 09:07 PM, said:

Alice Sun, on 16 December 2012 - 08:14 PM, said:

What's exactly the differences between ceramic, porcelain, and stoneware? I searched it on the internet, but still couldn't have a clear understanding about it.

Alice,

I'm kinda new at this myself, so here's how I understand things -- and if I'm wrong, I'm sure someone here will let me know.

"Ceramics" is a general term that covers anything made by forming and firing clay. There are industrial applications as well as artistic ones for ceramics, from bathroom tiles, toilets, and sinks to kitchen knives to pieces of the space shuttle.

"Stoneware" is a broad term for most mid-fire clays (cone 4-6) that aren't porcelain. Earthenware, by contrast, is low-fire clay (cone 04-cone 3).

"Porcelain" is a specific type of clay, and I confess I don't know a lot about it other than that can be either mid-range (around ^6) which isn't a "true" porcelain, or high-fire (cone 10-14).

Stoneware isn't limited to cone 4-6. Until the last decade or so it had to be above 6 to even be considered stoneware by most potters. Some of the best stonewares are cone 10 or above. Pricklypotter above gave a good description of porcelain. Some cone 6 porcelains (and they are true porcelains) are harder, more translucent, and ring louder than some cone 10 porcelains and it is therefore silly to call the inferior white clay fired to cone 10 "true" porcelain and not the cone 6 porcelain.

Jim

[yedrow]

Marcia,

You know, I didn't think about salt or ash from wood fired kilns when I wrote that. Intuitively though I would think that the clay-glaze interface is still represented as stoneware in those cases.

Joel.

[AtomicAxe]

Ceramic usually just refers to MOST non-metallic products that has been heat fused to a solid material. Just as JBaymore described. Pretty much it's a general term like painting or flooring. In the art field it refers to anything made of clay of some sort as the ground of the work. I.E you can have acrylic paintings on clay ... ceramics, you can put inorganic (sometimes organic) compounds your clay to fire them into a decorative surface ... ceramics, put a compound on a piece of metal and fuse it into a decorative surface ... enamel. Just semantics.

Stoneware is a clay body that has become vitreous (absorbs no water) thus is like a stone. Funny note, porcelain at high temps is stoneware, but stoneware at high temps is not always porcelain. Temperature has little to do with when a clay becomes vitreous as that depends on the clays maturity point of vitreousness ... but as a standard starts to go through a vitreous state around cone 1-4.

Porcelain is just a clay that uses primary sources of clay and binders in the body of the work and is of fine grade materials. Primarily kaolin. If the clay uses secondary or tertiary sources of clay (impure clays) like ball clay and red clays and/or fireclays composed of secondary clays, the clay body is no longer pure and is thus not considered porcelain any more since the iron in those clays turn grey to brown from impurities in reduction firing. To some degree purists consider porcelain ONLY cone 10 and higher since lower melting materials like gerstely borate, neph sy and ferro frits are deemed impure ... but really they should stop being picky IMO.