Is it glazed?

yes, it's glazed. As I said, the glazing gets darker when it's wet. Even washing it makes it darker.... until it dries.

I am certainly no expert, but it sounds like the glaze is more like a coat of plastic that has cracked allowing water to enter perhaps by capillary action within the thin layer between the plastic and the bowl. I would use it for decorative purposes.

Many years ago our Radioisotope Chemistry professor showed us a nice brown cup (might have even been Fiesta Ware) that sent the geiger counter screaming. Such things may still happen. We have a pretty mug that we appropriated from SIL's lower cabinet since she wasn't using it. When she later saw it in our coffee cup rotation, she let us know that she had been told it had too much lead. It now holds small cleaning brushes up beside the sink.

Rule of thumb with traditional ceramics--if it's not specifically labelled "food safe" assume it isn't. Most of the beautiful old glazes have lead. If it's a plastic base, as stated above, it's more likely to be safe(-ish), but if it's water permeable it's still not the best choice for serving in. Perhaps find clear glass inserts to use with them.

I don't believe it could be plastic! I assumed they were food safe because they're shaped like casserole dishes and such. Thanks, everyone. I'll try to get some photos tomorrow so you'll see what I'm talking about -- it's all stored away at the moment.

If they're newly made, they're probably safe. Probably. I got the feeling from your post that you'd had them for some time. The EU put in some strict rules awhile back. But there may be exceptions. I often see what looks like a casserole that I'm tempted by and find "decoration only" or "not for food" in the fine print. The darkening/lightening means water is getting into the ceramic, which a glass like glaze would not allow unless it had noticeable fissures. Either way, if water is getting through, so are bacteria and other things. I would play it safe, even though they're pretty.

I bought these on Terceira Island in 1996. I'm certain they were newly made at the time. I'm guessing they're what's called Earthenware. Will try to get pics later.

That's long enough ago that you really can't assume they're food safe, unfortunately. Really, glass inserts are the way to go if you want to use them.

If the glaze darkens when wet....it's not a glaze.
I would feel safe serving a sandwich and chips on them....btu maybe not something juicy and acedic like spaghetti and meatballs.

A sandwich and chips also probably wouldn't pick up heavy metals from it.

Is it the red clay with simple decoration? A shame the glaze is somehow compromised...moisture getting through.

I would use it for dry goods only. After testing for lead. I stock the 3M testers for any vintage ceramics. Though '96 is not that old. Just precaution.

Many old glazes weaken like the pyrex bowls with colors. The nesting ones. Probably detergents caused them to powder and weaken.

It's not just lead. It's also cadmium and a few others, especially in the warm colors.

There are also permeable glazes. It's been so long since I made pottery it's taken awhile to remember. They give a more matte finish, but aren't glassy and don't hold water. The glazes we used were probably full of lead, though. :) There was a ton of lead in the air from gasoline, already, so no one much cared what was coming out of a kiln. I shudder to think...

I thought there was lead in regular too?

omg... I was pulling out the pieces to take photos and saw this sticker!!! what exactly does a wine glass and a fork mean? LOL!!! assuming that's what it represents. :)

ETA: according to wiki, that's the International symbol for "food safe". Can anyone confirm whether these can be used in the oven??? I think all of the bottoms are unglazed.

I thought there was lead in regular too?

Yes. Although that does kind of make one wonder how it is that the great majority of people had exposure to lead in paint, in gas, in the air, in their pipes, in their dishes and glasses, etc, and yet most folks survived just fine.

ETA There's still lead in the air around busy roads. NIH recommends that people like me who live next to a busy road should soak their home-grown produce in a sink full of water and vinegar to remove it.

Yeah! Yes, food safe by the sticker! Problem solved. Pretty, too. The fork means general food, actually, and the wine glass means that it's okay for the things that soak up lead, like wine and honey. Together they mean stop worrying. :) I'm so pleased you found the sticker!!

Re oven, you said that they're "serving pieces", and also that at least one absorbed a lot of water. That makes me think they might be terracotta but also could just be clay. The problem is the water. If there's more water in the clay than can get out easily when heated, the dish could crack, or if it's too rapid a heat difference, it could shatter. If you just want to warm it, rather than cook in it, it should be fine. It will have been fired at a much higher temperature just to exist, and it really is the water that's the issue.

I had a pottery oven dish that cracked on the first use, so the company sent a replacement. That cracked on the second or third use, and I gave up. And that dish was specifically designed for cooking and I was careful about not causing a thermal shock from changing temperatures too fast.

If it were stoneware, it wouldn't soak up so much water with the green beans. I don't think it would if it were terracotta either, but terracotta does darken. Both stoneware and terracotta are fine, unglazed, at baking temperatures. Just don't go right from the oven to cold stone (put it on a rack or trivet). But I fear your dishes might just be clay (pottery), at which point, at least try it with something not too wet if you're going to put them in the oven.

Writersblock, people with high lead exposure from tins or cosmetics, or eating paint, showed cognitive deficits. Children are especially vulnerable, which is why it's so important to remove flaking lead paint. It tastes like candy. Painters used to chew on it too. But the epidemiologists and environmental health researchers look at statistical clusters using health, attendance, mandated test scores, employment records, etc., to find where there are deficits and do site investigations to see if there are pollutants that might be correlated with them. The fact is that people will survive if they can--you can cut and serve the air in parts of China, and people are surviving--but they weren't just fine, and things are actually much better now with a bigger population because while there are plenty of noxious particulates still being spewed, they're not as bad.

There are some extreme examples of lead poisoning in history, where people actually died, but even with high exposure, they're more likely to go gently mad. Some of the other heavy metals are less obvious. There are therapies that can, at least sometimes, remove them from the body. I saw one report that a kid was diagnosed as autistic who really had heavy metal poisoning. Fine art painters who chew their brushes (like chewing a pencil) end up with heavy metal poisoning. They don't die. But it's not good.

The great news is that unless the people who made PM's pretty pottery were lying thieves, we now know that no such thing is going to happen from using her dishes!!!

'....make one wonder how it is that the great majority of people had exposure
to lead in paint, in gas, in the air, in their pipes, in their dishes
and glasses, etc, and yet most folks survived just fine.'

Well, 'just fine' is actually in question. There have been large increases of various cancers and of course we have all these concerns that some people want to blame on vaccinations etc. while the lead was vaporizing from everyone's garage. Yes, TEL in Regular too, but lesser amounts.

plllog, I have a large oval serving platter, a large oval casserole dish, and at least two bowl/serving-type pieces. And a matching pitcher. lol! It's the casserole I'd want to use in the oven. :)

You can try it. I'd use it for an actual casserole (anything from lasagna to 1950's tuna bake), which isn't as wet. See how it does. And keep to 350°. And put it on a cloth or cork trivet when it comes out.

Well, 'just fine' is actually in question. There have been large increases of various cancers

While I don't disagree at all with plllog's post, that's my point, chas. Lead exposure was everywhere for well over a thousand years--the middle ages were well aware of what happened to the folks who made red lead and white lead pigments, for instance, but that didn't stop the rest of the populace from opting to use the products they produced. When I was in elementary school we were told that Rome fell because all the Romans got stupid from lead exposure from their drinking water, but it seems to me that current events cast some doubt on that theory. :)

So cancers are up, but lead exposure is down considerably.