diff --git a/ign.lua b/ign.lua
index ea2fa5a..c81663c 100644
--- a/ign.lua
+++ b/ign.lua
@@ -64,7 +64,7 @@ end
 rocks.register_vein=regv
 
 rocks.register_vein("default:nyancat",{
-  wherein="rocks:granite",
+  wherein={"rocks:granite"},
   miny=-160, maxy=20,
   radius={ average=10, amplitude=4, frequency=8 },
   density=100,
diff --git a/mapgen.lua b/mapgen.lua
index b619b22..6531b7d 100644
--- a/mapgen.lua
+++ b/mapgen.lua
@@ -26,7 +26,7 @@ rocksl.register_stratus=function(layer,name,param)
 end
 
 rocksl.register_vein=function(col,name,param)
- table.insert(col,{
+ local d={
    primary=name,
    wherein=param.wherein,
    miny=param.miny, maxy=param.maxy,
@@ -34,7 +34,8 @@ rocksl.register_vein=function(col,name,param)
    density=(param.density or 1),
    rarity=param.rarity,
    secondary=(param.ores or {}),
-  })
+  }
+ table.insert(col,d)
 end
 
 rocksl.layergen=function(layer, minp, maxp, seed)
@@ -136,11 +137,14 @@ rocksl.veingen=function(veins,minp,maxp,seed)
     },{x=(vrm*2)+1, y=(vrm*2)+1, z=(vrm*2)+1}
    )
    local iterations_count= (vein.rarity*side_length)^3
+   -- Resolve node names to id's
    iterations_count=iterations_count+(random:next(0,100)/100)
    local primary_ctx=minetest.get_content_id(vein.primary)
    for _,sec in pairs(vein.secondary) do sec.ctx=minetest.get_content_id(sec.ore) end
-   local wherein_ctx=minetest.get_content_id(vein.wherein)
-   --print("vein "..vein.primary.." ic="..iterations_count.." p="..primary_ctx.." w="..wherein_ctx)
+   --old:local wherein_ctx=minetest.get_content_id(vein.wherein)
+   local wherein_set={}
+   for _,wi in pairs(vein.wherein) do wherein_set[minetest.get_content_id(wi)]=true end
+   --print("vein "..vein.primary.." ic="..iterations_count.." p="..primary_ctx)
    for iteration=1, iterations_count do
     local x0=minp.x+ random:next(0,side_length)
     local y0=minp.y+ random:next(0,side_length)
@@ -148,7 +152,7 @@ rocksl.veingen=function(veins,minp,maxp,seed)
     local noise=noise_map:get3dMap_flat({x=x0-vrm, y=y0-vrm, z=z0-vrm})
     local noise_ix=1
     local posi = area:index(x0, y0, z0)
-    if ignore_wherein or (nodes[posi]==wherein_ctx) then
+    if ignore_wherein or wherein_set[nodes[posi]] then
      print("vein "..vein.primary.." @ "..x0..","..y0..","..z0.." vrm="..vrm)
      did_generate=1
      for x=-vrm, vrm do
@@ -157,7 +161,7 @@ rocksl.veingen=function(veins,minp,maxp,seed)
         local posc = {x=x+x0,y=y+y0,z=z+z0}
         posi = area:index(posc.x, posc.y, posc.z)
         local nv=noise[noise_ix]
-        if (ignore_wherein or (nodes[posi]==wherein_ctx)) and (((x^2)+(y^2)+(z^2))<((vein.radius.average+nv)^2)) then
+        if (ignore_wherein or wherein_set[nodes[posi]]) and (((x^2)+(y^2)+(z^2))<((vein.radius.average+nv)^2)) then
          nodes[posi]=primary_ctx
          local luck=random:next(0,99)
          for _,sec in pairs(vein.secondary) do
diff --git a/skarn.lua b/skarn.lua
index d62e81c..79b537e 100644
--- a/skarn.lua
+++ b/skarn.lua
@@ -2,8 +2,9 @@
 -- Skarn deposit
 --
 
-local CommonRarity=0.02
+local CommonRarity=0.02 --too high... should be like 0.013
 local CommonRadius=10
+local CommonWherein={ "rocks:granite" }
 
 minetest.register_node( "rocks:skarn", {  
 	description = S("Skarn"),
@@ -33,7 +34,7 @@ minetest.register_node( "rocks:skarn_malachyte", {
 })
 -- Chalcopyrite/Malachyte skarn mix
 rocks.register_vein("rocks:skarn",{
-  wherein="rocks:granite",
+  wherein=CommonWherein,
   miny=-160, maxy=20,
   radius={ average=CommonRadius, amplitude=3, frequency=5 },
   density=80, rarity=CommonRarity,
@@ -62,7 +63,7 @@ minetest.register_node( "rocks:skarn_galena", {
 })
 -- Pb Zn skarn mix
 rocks.register_vein("rocks:skarn",{
-  wherein="rocks:granite",
+  wherein=CommonWherein,
   miny=-160, maxy=20,
   radius={ average=CommonRadius, amplitude=3, frequency=5 },
   density=80, rarity=CommonRarity,
@@ -84,7 +85,7 @@ minetest.register_node( "rocks:skarn_magnetite", {
 })
 -- Fe skarn mix
 rocks.register_vein("rocks:skarn",{
-  wherein="rocks:granite",
+  wherein=CommonWherein,
   miny=-160, maxy=20,
   radius={ average=CommonRadius, amplitude=3, frequency=5 },
   density=80, rarity=CommonRarity,
@@ -112,7 +113,7 @@ minetest.register_node( "rocks:vermiculite", {
 })
 -- magnesite/vermiculite skarn mix
 rocks.register_vein("rocks:skarn",{
-  wherein="rocks:granite",
+  wherein=CommonWherein,
   miny=-160, maxy=20,
   radius={ average=CommonRadius, amplitude=3, frequency=5 },
   density=80, rarity=CommonRarity,