Permafrost?

[Matron Mother]

This is relatively shot post and I do apologize in advance for this, but I've been searching around for anything going into details about how permafrost works (I've looked into Frostburn, no luck there sadly), as in, are there spells that make objects permanently solid in never-melting ice, protected even from magical fire?

The purpose of this is I'm creating a weapon called the "Frozen Tuna", which is inspired from the old game Dark Cloud. I'm a big fan of Archaic Weapons/Armor, and am currently creating an RPG sourcebook with such items involved so I was wondering if anyone had any leads on Permafrost in general.

Thank you :)

[Venger]

Blue ice does what you want. Magic ice that never melts and can be used to make weapons, armor, and other stuff like furniture, beer glasses, and buildings. Frostburn, page 80

[Fizban]

A spell that makes an object permanently immune to fire? Nope. A spell that turns a creature into ice that might not melt normally? Flesh to Ice says they die if they melt, but doesn't say they won't normally melt. Burst of Glacial Wrath uses the creature's remaining hp (which for a tuna will almost certainly be -9, for 1hp remaining), but also gives them hardness 10, but also vulnerability to fire and says they instantly melt if reduced to -10 by magical fire- and makes no mention of them otherwise melting. If you gave the tuna the [fire] subtype first, such as via the original Mantle of the Firey Spirit* (in Sandstorm), then you would have a frozen tuna with the hardness of steel which would not melt from magical fire.

*Frostburn reduced the level and removed the gp cost on the cold version for some reason (permanent non-dispelable energy immunity is kinda huge), but SpC changed it to hour/level and has no mention of the fire version. So I guess you don't even need a pass.

Of course they actual way you would make this is the same as any other specific magic item. By making it up and then asking the DM. There are tons of magic items that say they're made of this or that wacky substance. Magic Item Compendium even reprints a bunch of Eberron items that were supposedly special Bind Elemental creations, but in MiC you can just use normal crafting feats, because it doesn't actually mean anything. The tuna is permanently frozen as part of the item creation process, and could even be immune to fire as part of the weapon's abilities.