Index: cookbook.lua
==================================================================
--- cookbook.lua
+++ cookbook.lua
@@ -709,14 +709,17 @@
 	local meta = stack:get_meta()
 
 	local curpage = meta:contains("pagenr") and meta:get_int("pagenr") or 1
 	local pagect = math.ceil(#book.pages / constants.recipes_per_cookbook_page)
 
-	if curpage > 1 and fields.pageback then
-		meta:set_int('pagenr', curpage - 1)
-	elseif curpage < pagect and fields.pagenext then
-		meta:set_int('pagenr', curpage + 1)
+	if fields.pageback or fields.pagenext then
+		if curpage > 1 and fields.pageback then
+			meta:set_int('pagenr', curpage - 1)
+		elseif curpage < pagect and fields.pagenext then
+			meta:set_int('pagenr', curpage + 1)
+		end
+		minetest.sound_play('sorcery_pgturn', { pos = pos, gain = 0.6 })
 	end
 
 	uinv:set_stack('main',idx,stack)
 	bookform(stack,user)
 end)

Index: itemclass.lua
==================================================================
--- itemclass.lua
+++ itemclass.lua
@@ -21,10 +21,11 @@
 		-- themselves) and items crafted from those materials.
 		-- the former includes only crafting materials, the
 		-- latter includes both.
 		gem = {
 			compat = 'gems';
+			finagle = function(g) return {data = sorcery.data.gems[g.id]} end;
 			groups = { 'gem', 'crystal'; };
 			predicate = function(name)
 				if minetest.get_item_group(name, 'sorcery_gem') ~= 0 
 				or minetest.get_item_group(name, 'sorcery_shard') ~= 0 then
 					return minetest.registered_items[name]._sorcery.material;

Index: lathe.lua
==================================================================
--- lathe.lua
+++ lathe.lua
@@ -56,10 +56,17 @@
 				inv:set_stack('preview',i,ItemStack())
 			end
 		end
 		return
 	end
+
+	local tmat = sorcery.itemclass.get(tool:get_name(),'material')
+	local wmat = sorcery.itemclass.get(wkpc:get_name(),'material')
+	-- obey level restrictions. TODO honor Rend
+	if (wmat and wmat.data.level or 0) > (tmat and (tmat.data.maxlevel or tmat.data.level) or 0) then
+		return
+	end
 
 	local tech = sorcery.lathe.tooltech(tool)
 	local rec = R[wkpc:get_name()][tech]
 	tech = sorcery.lathe.techs[tech]
 
@@ -164,15 +171,24 @@
 	end;
 	on_metadata_inventory_put = sorcery.lathe.update;
 	on_metadata_inventory_take = function(pos, list, idx, stack, user)
 		if list == 'preview' then
 			local l = sorcery.lathe.get(pos,idx,stack:get_count())
-
 			if sorcery.lathe.techs[l.tech].consume then
 				l.tool:take_item(l.cost)
 			elseif sorcery.lathe.techs[l.tech].dmg then
-			--TODO wear down tool
+				local mat = sorcery.itemclass.get(l.tool,'material')
+				local mmat = sorcery.itemclass.get(l.wkpc,'metal')
+				local dur = 100
+				local lfac = 1
+				if mat then
+					local dur = mat.data.durability or dur
+					lfac = (mmat and mmat.data.level or 1) /
+						(mat.data.maxlevel or mat.data.level or 1)
+				end
+				local ch = 65535 / dur
+				l.tool:add_wear(4 * ch * l.cost * lfac)
 			end
 			l.wkpc:take_item(l.qty)
 			l.inv:set_stack('tool', 1, l.tool)
 			l.inv:set_stack('workpiece', 1, l.wkpc)
 			minetest.sound_play('sorcery_clank', { pos = pos, gain = 0.9 })

Index: writing.lua
==================================================================
--- writing.lua
+++ writing.lua
@@ -479,10 +479,11 @@
 			if fields.nextpage or fields.prevpage then
 				local page = math.max(1,bm:get_int('pagenr'))
 				if     fields.nextpage then page = page + 1
 				elseif fields.prevpage then page = page - 1 end
 				bm:set_int('pagenr',math.max(1,page))
+				minetest.sound_play('sorcery_pgturn', { pos = pos, gain = 0.6 })
 				changed = true
 			end
 
 			-- handle retitle request
 			if fields.title then