There are many things this could be, some based on portland cement, and some based on polymers known as Rhino Snot, which has been used by the military:

https://en.wikipedia.org/wiki/Soil_cement

I'm only aware of it after viewing a video about potential moon bases and roads, because the fine dust is a problem, and rhino snot was mentioned, but discarded; They are instead focused on lasers or using focused sunlight to melt the lunar soil into a glass road. I foresee massive problems with a lot they are proposing, and immense cost, and... *why*.

It's tiki torch fuel, opened but mostly full bottles dropped off at Goodwill at end of summer, big bottle $1.99. Bought several bottles. The one I have handy does not show content and percentages, but other bottle said about 96% mineral oil, and the rest is natural anti-bug stuff like citronella oil and lemongrass oil. Yes, it sure does evaporate slow, takes a day or two or more after cleaning, which is not a problem as I'm not going to worry about a tiny bit of something that mixes fine with the oil. Also, slow evap makes it super safe, not volatile, I think needs a wick to burn. Excellent chain cleaner, was quite surprised how well it dissolved 75W-90 synthetic gear lube that is well pasted due to suspension of ultrafine steel powder, that's the clue that it's time to clean the chain and relube.

Also, excellent bug spray (my apartment and kitchen is spotless but it's a big building with other more careless residents), the STEM non-toxic bug spray is 6.2% geraniol, 0.5% lemongrass oil, and 93.3% "other ingredients" and fine print says white mineral oil, and a couple other chems. When I ran out, I looked and the torch fuel looked close enough, refilled the bottle, kills bugs (roaches) the same, just takes a bit longer. Sprayed on fabric or cardboard, and yeah, will be stained for months while it slowly evaporates, if not washed sooner. Marvel Mystery Oil is mostly mineral oil, with a bit of stoddard solvent (white spirit) and tiny amounts of other chems. So there's that. Just wide uses. Like when I had Coleman Fuel around, had half a dozen uses for that, when it was $5/gal and not $20/gal.

Probably a mislabel by the manufacturer. Mineral spirits and mineral oil are in the same class of compounds with mineral spirits being made up of smaller, more volatile molecules and mineral oil being made up of larger, far less volatile molecules. Think Coleman fuel vs baby oil. Mineral spirits flows better and feeds a wick better than mineral oil would. Both will burn but mineral oil would be a relatively slow, low flame compared to mineral spirits.

An SDS for Tiki/Citronella fuel says that it is mixture of “Distillates (petroleum), hydro treated light” and “Distillates (petroleum), hydro treated middle” of unstated proportions. In layman’s terms it is likely a mixture of mineral spirits and something resembling kerosene. Kerosene is a bit less volatile than mineral spirits which is why it takes a little longer to evaporate.

Thanks for the explanation, it might be like you said. The bottle I have that doesn't list ingredients is screwdriver-yellow liquid, that's what I've been using as chain cleaner, and it's a tiny bit volatile as it will smell up my room a bit without ventilation, in the first day after chain cleaning, and evaporate to be mostly dry on the outside after several days.

The other bottle with more info (not handy at the moment) is clear as water, and that's the one I used to refill my bugspray bottle that was originally mostly mineral oil and clear, according to the label. I wonder about the differences. The clear tiki does kill roaches, just not quite as quick as the original spray, my guess was because it doesn't have 6% geraniol, but spray one up on the wall where I can't reach, and it immediately falls to the floor, just crawls around a bit. So whether mineral oil or closer to kero, the bugs don't like it. The original contents says "safe for use around kids and pets", I think that would favor mineral oil, but I think it means safe for simple contact, not ingestion.

Anyway, it's a great chain cleaner in the Park Tool whirlygig, and when purchased at goodwill, dirt cheap. I've actually been reusing after sticking a magnet in it and pulling out all the metal sludge, and then keeping in a jar, so these bottles should last me a long time.

Two other facts: I tried dissolving paraffin wax in the yellow tiki fuel, nope (at least at room temp), not after sitting weeks in it, that may say something. (I was hoping to clean and lube chain in one step. But once I go back to wax melt, I won't need to do chain cleaning.) Also, wetting the top of a store price sticker, let sit a few minutes, allows the sticker to pull off easy, usually with no sticky left behind, and no damage to anything.