Add things

mods/rgt_materials/init.lua

@@ -16,9 +16,45 @@
       - Gravel
 --]]
 
+-- MARK: - Coal
+
+
+rgt.register_item("coal_lump", {
+    inventory_image = "rgt_coal_lump.png",
+    groups = {furnace_fuel = 1}
+})
+
+rgt.register_node("coal_ore", {
+    tiles = {"rgt_stone.png^rgt_coal_ore.png"},
+    drop = "coal_lump",
+    groups = {stone = 1}
+})
+
+minetest.register_ore {
+    ore_type = "scatter",
+    ore = "coal_ore",
+    wherein = "stone",
+    
+    clust_scarcity = 4 * 4 * 4,
+    clust_num_ores = 8,
+    clust_size = 3,
+    
+    noise_params = {
+        offset = 0,
+        scale = 1,
+        spread = {x = 100, y = 100, z = 100},
+        seed = 1189,
+        octaves = 3,
+        persistence = 0.7
+    },
+}
+
+
+-- MARK: - Iron
+
 rgt.register_item("iron_ingot", {
     inventory_image = "rgt_iron_ingot.png",
-    groups = {furnace_fuel = 1}
+    groups = {arc_furnace_meltable = 1}
 })
 
 rgt.register_item("iron_lump", {
@@ -57,7 +93,7 @@ minetest.register_ore {
 }
 
 
-
+-- MARK: - Gold
 
 rgt.register_item("gold_ingot", {
     inventory_image = "rgt_gold_ingot.png",