The only reader-added tag so far is "Unzan light bulb".

Also, we don't appear to have a "rock salt" tag, but I'm not sure it applies here anyway.

Moonspeaker said:

The only reader-added tag so far is "Unzan light bulb".

Also, we don't appear to have a "rock salt" tag, but I'm not sure it applies here anyway.

That white stuff doesn't belong on rock salt, if that's salt.

Jarlath said:

That white stuff doesn't belong on rock salt, if that's salt.

It definitely looks like salt-block lamps I’ve seen before, though I’ll grant none had that sporadic encrustation of white salt crystals.

Moonspeaker said:

It definitely looks like salt-block lamps I’ve seen before, though I’ll grant none had that sporadic encrustation of white salt crystals.

Most of the lamps I've seen have less foamy looking encrusted bits.