diff --git a/changelog.txt b/changelog.txt
index 4ac1eaf..92e3c80 100644
--- a/changelog.txt
+++ b/changelog.txt
@@ -1,4 +1,10 @@
 ---------------------------------------------------------------------------------------------------
+Version: 0.5.7
+Date: 2021-06-05
+  Changes:
+    - K2 & Dectorio: Ploppable rock recipes now require zircon
+    - Reduced zircon richness around starting area a little bit more, yet again
+---------------------------------------------------------------------------------------------------
 Version: 0.5.6
 Date: 2021-02-22
   Features:
diff --git a/data-updates.lua b/data-updates.lua
index d19edab..294f87d 100644
--- a/data-updates.lua
+++ b/data-updates.lua
@@ -4,21 +4,7 @@ require("zircon-matter")
 require("map-gen-preset-updates")
 require("omni")
 require("strange-matter")
-
-local util = require("data-util");
+require("zircon-rocks")
+
 
 
--- Add zircon to rocks
-local min = 9
-local max = 11
-if mods["alien-biomes"] then
-  min = 5
-  max = 7
-end
-for _, e in pairs(data.raw["simple-entity"]) do
-  if (e.subgroup == "grass" or e.subgroup == "wrecks") and e.name:match("rock%-") then
-    local adjusted_max = e.name:match("huge") and max * 2 or max
-    local adjusted_min = e.name:match("huge") and min * 2 or min
-    util.add_minable_result("simple-entity", e.name, {name="zircon", amount_min=adjusted_min, amount_max=adjusted_max})
-  end
-end
diff --git a/data-util.lua b/data-util.lua
index 84b7785..6ce0745 100644
--- a/data-util.lua
+++ b/data-util.lua
@@ -54,6 +54,19 @@ function util.contains(table, sought)
   return false
 end
 
+-- Set/override a technology's prerequisites
+function util.set_prerequisite(technology_name, prerequisites)
+  local technology = data.raw.technology[technology_name]
+  if technology then
+    technology.prerequisites = {}
+    for i, prerequisite in pairs(prerequisites) do
+      if data.raw.technology[prerequisite] then
+        table.insert(technology.prerequisites, prerequisite)
+      end
+    end
+  end
+end
+
 -- Add a prerequisite to a given technology
 function util.add_prerequisite(technology_name, prerequisite)
   local technology = data.raw.technology[technology_name]
@@ -541,10 +554,10 @@ end
 
 -- Set recipe icons
 function util.set_item_icons(item_name, icons)
-  if data.raw.recipe[item_name] then
-    data.raw.recipe[item_name].icons = icons
-    data.raw.recipe[item_name].icon = nil
-    data.raw.recipe[item_name].icon_size = nil
+  if data.raw.item[item_name] then
+    data.raw.item[item_name].icons = icons
+    data.raw.item[item_name].icon = nil
+    data.raw.item[item_name].icon_size = nil
   end
 end
 
diff --git a/info.json b/info.json
index 960f289..6c6c047 100644
--- a/info.json
+++ b/info.json
@@ -1,6 +1,6 @@
 {
     "name": "bzzirconium",
-    "version": "0.5.6",
+    "version": "0.5.7",
     "factorio_version": "1.1",
     "title": "Zirconium",
     "author": "Brevven",