When do you use "molten" vs "melted"?

“molten” historically was simply the past participle of “melt” and thus synonymous with “melted”
but now is used as an adjective to refer to things that have been melted by very high heat and are hot in their liquid form like metal or rock or wax. “Melted” would be used otherwise.

Strangely, I guess, I use molten for hot things (iron, lava), and melted for cold things (ice, snow, chocolate).

@rebbel Same. Melted lava just doesn’t make sense. Molten ice is weird as well.

Molten lava, melted ice!

I would say that molten denotes a state, whereas melted refers to the result of a process. Something can persist in a molten state, but melted is about a change of states. Something can be molten without ever having been a solid; but melted is specific to something that has been subject to the action of melting.

I can think of figurative uses of both that don’t reflect this distinction (“she melted in his arms,” “her molten gaze transfixed him”), but I believe it’s present in any literal uses.

Molten is for something that takes an unusual amount of heat, and that is still that hot.

Melted is for anything that melted, even in the past, and that might now be cool.

@Zaku, when I melt some Baker’s unsweetened chocolate for certain recipes, it’s just in a small pan on the stove. It takes very little heat. But it isn’t cold when I’m done, it’s warm. And the melting must be in the past, or it wouldn’t be meltED, it would be meltING (or solid again). It’s going into the recipe warm and not returning to its former state or condition. Is that melted or molten in your lexicon?

When the wax runs down the side of the candle, is it melting or molten? When it’s hardened in a puddle on the tablecloth, is it melted or not? Does using “melted” require awareness of its former premelted state? If not, how would you know that its present condition is softened and reshaped from its former one? Don’t you have to make the distinction between state and process?

@Zaku Melted is for anything that melted, even in the past, and that might now be cool.

I was taught that you can’t use a word in the definition of itself.

@Jeruba Probably neither. In my lexicon, still-warm and pliable chocolate chips in a cookie would probably be called “gooey.”

Molten chocolate chips in a cookie implies to me dangerously too hot to want to eat.

I probably wouldn’t use the word melted for cookie chips unless they had flowed more than cookie chips usually do.

Chocolate is kind of expected to be melted or formed into shape for food, so in the case of chocolate, I might tend to expect that “melted chocolate” would still be warm enough to flow or ooze, or chocolate that had oozed around more than usual in a chip cookie. On the other hand, unless you eat your cookies soon, or keep them warm and gooey until eaten, they will eventually cool off, but since I expect chocolate to be formed, and usually chocolate chips in cookies don’t melt all that much, I would tend not to use the word melted to refer to them in their eventual cooled state.

Similarly, I would be afraid to eat a sandwich if someone said the cheese was still “molten”, but not a melted cheese sandwich.

Where I would use “melted” for cool objects, would be for things that are not expected to melt, such as chocolate bars or pens or headlights or plastic dolls or army men, who melted and then cooled off but are now deformed.

@smudges That’s a rule used to teach/get students not to make circular definitions. In that sentence I was not trying to define melted, but to explain a distinction between melted and molten, where the term melted itself is already assumed to be understood.

Molten when is still hot like lava, and melted when cooled off like cheese, and chocolate.

Molten is very hot, as others have said, like lava and steel. Something that is very hard and solid that is turned to liquid at a high temperature.

Melted is for food and plastic and even ice cubes, and things that melt at a lower temperature.

Also, molten I often associate with liquid that is moving or running, while melted is more like the substance that is in place but now soft from heat. Melt does not necessarily mean melted to the state of being a liquid, it can just be soft.

Molten lava is redundant, because lava is melted rock. The rock is in a molten state.

Molten is more like a state of being as mentioned above by another jelly, and what I just wrote in the sentence immediately above, but the rules are imperfect, and so I would say it also is something that is memorized or just sounds right from usage.

@Zaku Understood. ‘Scuse my comment. ;o)

@smudges No worries!

@JLeslie Molten lava is not redundant because there is also cooled non-molten lava.

@Zaku Isn’t it igneous rock? Or, lava rock? I didn’t see on your link the term non-molten lava, although I admit I am far from being an expert in lava terminology.

We need our Hawaiian jellies on this Q. I really don’t know for sure the proper terminology.

It’s not that I wouldn’t say molten lava; you make a good point; molten clarifies it’s currently in a liquid state. I have never heard the term non-molten lava, but I haven’t talked about lava since K-12, except for lava rocks in my garden fifteen years ago.

I wasn’t saying that people often say “non-molten lava”; I was just saying “molten lava” is not redundant, because you wrote “Molten lava is redundant, because lava is melted rock”.

I just meant to say that “molten lava” is not redundant, because “molten” means ”currently liquefied and/or glowing due to heat”, and lava without the world molten can mean lava that was once molten in the past but is no longer molten.

I’ve heard of molten cheese and melted cheese. Likewise for chocolate. I think the difference is temperature, and the molten version must cool before it’s eaten.

@Zaku I wasn’t arguing, I don’t think you are either, I just really don’t know what’s considered correct.

I’m going to send to HJ and TW.

@JLeslie I’ve just been trying to explain.

When lava cools, it is simply called lava. It can at times be termed lava rock or cinder when it breaks up into small rocks or pebbles.

Science uses the Hawaiian terms to denote the 2 types of lava. The smooth type is called pahoehoe, and the crumbly type is a’a. I think it’s usually written as aa in English. It’s pronounced ah-ah. To pronounce it correctly, there’s a glottal stop between the 2 sounds.

Molten rock – flowing lava

Melted ice or snow – - turns into water.

Ach, @ragingloli, always with the controversial questions.

English is so difficult. So many exceptions, so many multiple meanings. So many different dialects around the US, let alone the world.