I separated the ores from rocks, to give freedom of choose to users.

Merge branch 'modpack'.

a.txt

@@ -16,6 +16,13 @@ Features
 * git clone git://repo.or.cz/rocks.git ([show](http://repo.or.cz/rocks.git/))
 * (old) Git clone: [https](https://gitorious.org/mt/rocks.git)
 
+This mod nor minetest_game/default do not define meaningful biomes. 
+So if you do not want unlimited grassland I suggest installing the 
+[Paramat's biomesdev mod](https://github.com/paramat/biomesdev) and adding 
+"rocks?" to depends.txt file inside the biomesdev folder. This is needed, 
+becouse "rock" overrides the standard biome registration callback to patch 
+in it's own sedimentary rocks.
+
 Screenshots
 -----------
 
@@ -42,13 +49,6 @@ Is implemented by modifiing MGv7 biomes to use rocks's sedimentary rocks.
 This means that you need mapgen v7 enabled. I also suggest enabling caves 
 and dungeons, as they are cool. 
 
-This mod nor minetest_game/default however do not define meaningful biomes. 
-So if you do not want unlimited grassland I suggest installing the 
-[Paramat's biomesdev mod](https://github.com/paramat/biomesdev) and adding 
-"rocks?" to depends.txt file inside the biomesdev folder. This is needed, 
-becouse "rock" overrides the standard biome registration callback to patch 
-in it's own sedimentary rocks.
-
 Soil is normlly 50-70 cm deep in real life, so I made soil (dirt) only 1 
 block thick. Under this thin layer of dirt an sedimentary layer is located. 
 In RL, there is clay and other stuff.
@@ -66,3 +66,33 @@ there.
 
 Spawn simillary to coal, but not as large.
 
+The Igenous layer
+--------------
+
+Default stone is aliased to basalt, but for some reason the alias is not 
+working so please treat stone as basalt until I find way to fix it.
+
+Everything below sedimentary and (unimp) metamorphic layer is of igneous origin. Primary rock is basalt. But about half of basalt is replaced by granite. Some smaller fraction (like 20%) is then replaced by diorite and gabbro.
+These are the primary rocks, and more should come.
+
+### Mineral distribution
+
+Mineral ore is placed only in nodes of correct rock and only if the region 
+for the ore is right. These "mineral biomes" can and do overlap and change 
+every like 100 nodes. Following regions are defined:
+
+| Region  | minerals
+|---------|----------
+| Copper  | Chalcopyrite, Malachyte
+| Pb/Zn   | Sphalerite, Galena
+| Iron    | Magnetite
+
+### Skarn deposits
+
+Are larg-ish (15-20m) blobs of skarn stone. They spawn only in granite and 
+limestone. Copper, Lead, Zinc and Iron ores often enrich the skarn stone. 
+Some deposits may (unimp) contain considerable amounts of Molybenium, 
+Uranium and Wolfram ores.
+
+Concentration of the minerals is quite high, as to regard the player for 
+finding a not-so-common skarn vein.

mineral/depends.txt

@@ -0,0 +1,2 @@
+rocks
+default

mineral/init.lua

@@ -0,0 +1,26 @@
+--
+-- The minerals mod.
+--
+
+minetest.log("info","/mineral mod initializing")
+
+-- Load translation library if intllib is installed
+
+if (minetest.get_modpath("intllib")) then
+	dofile(minetest.get_modpath("intllib").."/intllib.lua")
+	S = intllib.Getter(minetest.get_current_modname())
+	else
+	S = function ( s ) return s end
+end
+
+mineral={}
+mineral.noise={}
+
+local print=function(text)
+ minetest.log("info","/mineral "..text)
+end
+
+local modpath=minetest.get_modpath(minetest.get_current_modname())
+
+dofile(modpath.."/skarn.lua")
+

mineral/skarn.lua

@@ -2,25 +2,6 @@
 -- Skarn deposit
 --
 
-local CommonRarity=40 --too high... should be like 76
-local CommonRadius=10
-local CommonWherein={ "rocks:granite", "rocks:limestone" }
-
-minetest.register_node( "rocks:skarn", {  
-	description = S("Skarn"),
-	tiles = { "rocks_Skarn.png" },
-	groups = {cracky=3, stone=1}, 
-	is_ground_content = true, sounds = default.node_sound_stone_defaults(),
-})
-
--- skarn deposit
-rocks.register_vein("rocks:skarn",{
-  wherein=CommonWherein,
-  miny=-320, maxy=300,
-  radius={ average=CommonRadius, amplitude=0.16, frequency=8 },
-  density=80, rarity=CommonRarity,
- })
-
 local function GetNoiseParams()
  return {
   scale=1, offset=0, seed=rocksl.GetNextSeed(), octaves=1, persist=1,
@@ -29,80 +10,74 @@ end
 
 -- ores have to be redefined for skarn background
 
-   -- Todo:
-   -- There is also a chance of isolated lapis crystals, Gold
-   -- Molybdenite with Cu
-   -- wollastonite with Fe
-   -- enrichments: scheelite and wollastonite
-
 -- Chalcopyrite
-minetest.register_node( "rocks:skarn_chalcopyrite", {  
+minetest.register_node( "mineral:skarn_chalcopyrite", {  
 	description = S("Chalcopyrite"),
-	tiles = { "rocks_Skarn.png^rocks_Chalcopyrite.png" },
+	tiles = { "rocks_Skarn.png^mineral_Chalcopyrite.png" },
 	groups = {cracky=3}, 
 	is_ground_content = true, sounds = default.node_sound_stone_defaults(),
 })
 -- Malachyte
-minetest.register_node( "rocks:skarn_malachyte", {  
+minetest.register_node( "mineral:skarn_malachyte", {  
 	description = S("Malachyte"),
-	tiles = { "rocks_Skarn.png^rocks_Chalcopyrite.png" },
+	tiles = { "rocks_Skarn.png^mineral_Chalcopyrite.png" },
 	groups = {cracky=3}, 
 	is_ground_content = true, sounds = default.node_sound_stone_defaults(),
 })
 -- Chalcopyrite/Malachyte skarn mix
-rocksl.CopperNoise=GetNoiseParams()
+mineral.noise.Copper=GetNoiseParams()
 minetest.register_ore({
  wherein="rocks:skarn",
- ore="rocks:skarn_chalcopyrite",
+ ore="mineral:skarn_chalcopyrite",
  clust_size=3,
  clust_num_ores=12,
  clust_scarcity=4^3,
  noise_treshold=0.333,
- noise_params=rocksl.CopperNoise
+ noise_params=mineral.noise.Copper
  })
 minetest.register_ore({
  wherein="rocks:skarn",
- ore="rocks:skarn_malachyte",
+ ore="mineral:skarn_malachyte",
  clust_size=3,
  clust_num_ores=11,
  clust_scarcity=4^3,
  noise_treshold=0.333,
- noise_params=rocksl.CopperNoise
+ noise_params=mineral.noise.Copper
  })
 
 -- Sphalerite
-minetest.register_node( "rocks:skarn_sphalerite", {  
+minetest.register_node( "mineral:skarn_sphalerite", {  
 	description = S("Sphalerite"),
-	tiles = { "rocks_Skarn.png^rocks_sphalerite.png" },
+	tiles = { "rocks_Skarn.png^mineral_sphalerite.png" },
 	groups = {cracky=3}, 
 	is_ground_content = true, sounds = default.node_sound_stone_defaults(),
 })
 -- Galena
-minetest.register_node( "rocks:skarn_galena", {  
+minetest.register_node( "mineral:skarn_galena", {  
 	description = S("Galena"),
-	tiles = { "rocks_Skarn.png^rocks_galena.png" },
+	tiles = { "rocks_Skarn.png^mineral_galena.png" },
 	groups = {cracky=3}, 
 	is_ground_content = true, sounds = default.node_sound_stone_defaults(),
 })
 -- Pb Zn skarn mix
-rocksl.PbZnNoise=GetNoiseParams()
+mineral.noise.PbZn=GetNoiseParams()
 minetest.register_ore({
  wherein="rocks:skarn",
- ore="rocks:skarn_sphalerite",
+ ore="mineral:skarn_sphalerite",
  clust_size=3,
  clust_num_ores=9,
  clust_scarcity=4^3,
  noise_treshold=0.38,
- noise_params=rocksl.PbZnNoise
+ noise_params=mineral.noise.PbZn
  })
 minetest.register_ore({
  wherein="rocks:skarn",
- ore="rocks:skarn_galena",
+ ore="mineral:skarn_galena",
  clust_size=3,
  clust_num_ores=10,
  clust_scarcity=4^3,
  noise_treshold=0.38,
- noise_params=rocksl.PbZnNoise
+ noise_params=mineral.noise.PbZn
  })
    -- marble and hornfels, as well as unchanged limestone.
    -- { ore="rocks:marble", percent=10 },
@@ -111,22 +86,22 @@ minetest.register_ore({
    -- { ore="rocks:skarn_sphalerite", percent=25 },
 
 -- Magnetite
-minetest.register_node( "rocks:skarn_magnetite", {  
+minetest.register_node( "mineral:skarn_magnetite", {  
 	description = S("Magnetite"),
-	tiles = { "rocks_Skarn.png^rocks_Magnetite.png" },
+	tiles = { "rocks_Skarn.png^mineral_Magnetite.png" },
 	groups = {cracky=3}, 
 	is_ground_content = true, sounds = default.node_sound_stone_defaults(),
 })
 -- Fe skarn mix
-rocksl.IronNoise=GetNoiseParams()
+mineral.noise.Iron=GetNoiseParams()
 minetest.register_ore({
  wherein="rocks:skarn",
- ore="rocks:skarn_magnetite",
+ ore="mineral:skarn_magnetite",
  clust_size=3,
  clust_num_ores=13,
  clust_scarcity=4^3,
  noise_treshold=0.3,
- noise_params=rocksl.IronNoise
+ noise_params=mineral.noise.Iron
  })
    -- marble and hornfels, as well as unchanged limestone.
    -- { ore="rocks:marble", percent=10 },
@@ -134,16 +109,16 @@ minetest.register_ore({
    -- { ore="rocks:skarn_magnetite", percent=40 },
 
 -- Magnesite
-minetest.register_node( "rocks:skarn_magnesite", {
+minetest.register_node( "mineral:skarn_magnesite", {
 	description = S("Magnesite"),
-	tiles = { "rocks_Skarn.png^rocks_Magnesite.png" },
+	tiles = { "rocks_Skarn.png^mineral_Magnesite.png" },
 	groups = {cracky=3}, 
 	is_ground_content = true, sounds = default.node_sound_stone_defaults(),
 })
 -- Vermiculite (fixme: move to CommonRocks)
-minetest.register_node( "rocks:vermiculite", {
+minetest.register_node( "mineral:vermiculite", {
 	description = S("Vermiculite"),
-	tiles = { "rocks_Vermiculite.png" },
+	tiles = { "mineral_Vermiculite.png" },
 	groups = {crumbly=3}, 
 	is_ground_content = true, sounds = default.node_sound_stone_defaults(),
 })

modpack.txt

@@ -0,0 +1 @@
+# This is now a modpack, for you to ask why :)

rocks/ign.lua

@@ -37,13 +37,13 @@ minetest.register_node( "rocks:gabbro", {
 local reg=function(name,param)
  minetest.register_ore({
    ore    = name,
-   wherein= { "mapgen_stone" },
+   wherein= { "mapgen_stone", "default:stone", "rocks:basalt" },
    ore_type       = "scatter",
    clust_scarcity = 10^3,
    clust_num_ores = 20^3,
    clust_size     = 20,
    height_min     = -31000,
-   height_max     = -5,
+   height_max     = 28,
    noise_treshhold=param.treshold,
    noise_params={
           offset = 0, scale = 1, octaves = 3, persist = 0.5,

rocks/skarn.lua

@@ -0,0 +1,30 @@
+--
+-- Skarn deposit
+--
+
+local CommonRarity=40 --too high... should be like 76
+local CommonRadius=10
+local CommonWherein={ "rocks:granite", "rocks:limestone", "air" }
+
+minetest.register_node( "rocks:skarn", {  
+	description = S("Skarn"),
+	tiles = { "rocks_Skarn.png" },
+	groups = {cracky=3, stone=1}, 
+	is_ground_content = true, sounds = default.node_sound_stone_defaults(),
+})
+
+-- skarn deposit
+rocks.register_vein("rocks:skarn",{
+  wherein=CommonWherein,
+  miny=-320, maxy=300,
+  radius={ average=CommonRadius, amplitude=0.16, frequency=8 },
+  density=80, rarity=CommonRarity,
+ })
+
+   -- Todo:
+   -- There is also a chance of isolated lapis crystals, Gold
+   -- Molybdenite with Cu
+   -- wollastonite with Fe
+   -- enrichments: scheelite and wollastonite
+
+-- ~ Tomas Brod