Yeah, I wasn't aware that more specific domains were needed, but it makes sense that it does.
I got a language file working now too, the only issue with it is that the names aren't pluralized when you have more than one boulder in a stack. But I'm willing to live with that.
It looks like this:
{
"item-boulder-chalk": "Chalk boulder",
"item-boulder-chert": "Chert boulder",
"item-boulder-conglomerate": "Conglomerate boulder",
"item-boulder-limestone": "Limestone boulder",
"item-boulder-claystone": "Claystone boulder",
"item-boulder-granite": "Granite boulder",
"item-boulder-sandstone": "Sandstone boulder",
"item-boulder-shale": "Shale boulder",
"item-boulder-basalt": "Basalt boulder",
"item-boulder-peridotite": "Peridotite boulder",
"item-boulder-phyllite": "Phyllite boulder",
"item-boulder-slate": "Slate boulder",
"item-boulder-obsidian": "Obsidian boulder",
"item-boulder-bauxite": "Bauxite boulder",
"item-boulder-andesite": "Andesite boulder",
}