as I mentioned earlier. Luckily, we don't need to use our lantern for the end all be all.
Use one of the crystals and stick that inside your mining crate - carry the mining crate with you in and out of the mine and it'll also reduce left behind issues, personally I only use 1 crate to mine with and don't even bother with the horse - when you're around iron and adelite - often times its easier to A) buy replacement ingots or b) use just one crate to mine with, because generally, there's one, maybe two ore veins that are usable for that tier, and generally, that's less than one crate
Even if its not less than one crate
You can actually throw the ORE to any spot in the cave, and leave it there (at least for this version, dunno if it remains on reload but I think it does. It definitely remains as long as you leave the current session running)
So yeah. Crystal. They'll give you /juuusst/ barely enough light through the crate to see what you're doing - just keep the crate in arm's reach