diff --git a/mapgen_oreplanet.lua b/mapgen_oreplanet.lua
index a4d859a..bf3297c 100644
--- a/mapgen_oreplanet.lua
+++ b/mapgen_oreplanet.lua
@@ -55,7 +55,15 @@ planetoids.mapgen_oreplanet = function(minp, maxp, vm, area)
 				data[index] = c_base
 				for _,ore in pairs(planetoids.ores) do
 					if planet_n > ore.chance then
-						data[index] = ore.id
+						if ore.id then
+							-- "plain" layer
+							data[index] = ore.id
+
+						elseif ore.id_list then
+							-- mixed layer
+							data[index] = ore.id_list[math.random(1,#ore.id_list)]
+						end
+
 						break
 					end
 				end
diff --git a/ores.lua b/ores.lua
index 9a71e4d..6e9b178 100644
--- a/ores.lua
+++ b/ores.lua
@@ -10,22 +10,20 @@ register_ore({
 })
 
 register_ore({
-	id = minetest.get_content_id("default:stone_with_mese"),
-	chance = 1.1
-})
-
-register_ore({
-	id = minetest.get_content_id("default:stone_with_iron"),
+	id_list = {
+		minetest.get_content_id("default:stone_with_mese"),
+		minetest.get_content_id("default:stone_with_copper"),
+		minetest.get_content_id("default:stone_with_iron"),
+	},
 	chance = 1.0
 })
 
 register_ore({
-	id = minetest.get_content_id("default:stone_with_gold"),
-	chance = 0.99
-})
-
-register_ore({
-	id = minetest.get_content_id("default:stone_with_copper"),
+	id_list = {
+		minetest.get_content_id("default:stone_with_iron"),
+		minetest.get_content_id("default:stone_with_gold"),
+		minetest.get_content_id("default:stone_with_copper"),
+	},
 	chance = 0.98
 })