diff --git a/CHANGELOG.md b/CHANGELOG.md
index b7bf53774..3125c8f7f 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -13,6 +13,7 @@
 - Fixed duplicate mixer recipes for rose gold and sterling silver @Pyritie
 - Fixed mechanical mixers requiring an alloy that needed that tier of mixer @Pyritie
 - Finally fixed all the issues with upgrading the toolbelt - now you can safely dye and undye, upgrade with and without tools inside it, etc (#368) @Pyritie
+- Fixed a dupe with certus quartz @Pyritie
 
 ## [0.10.9] - 10-08-2025
 ### Changes
diff --git a/kubejs/server_scripts/gregtech/recipes.materials.js b/kubejs/server_scripts/gregtech/recipes.materials.js
index 60df5f9f7..10e47891b 100644
--- a/kubejs/server_scripts/gregtech/recipes.materials.js
+++ b/kubejs/server_scripts/gregtech/recipes.materials.js
@@ -775,7 +775,7 @@ function registerGTCEUMetalRecipes(event) {
 			.id(`shapeless/mortar_chipped_${material.getName()}`)
 
 		let amount = 9;
-		if (material === GTMaterials.NetherQuartz || material === GTMaterials.Amethyst)
+		if (material === GTMaterials.NetherQuartz || material === GTMaterials.CertusQuartz || material === GTMaterials.Amethyst)
 			amount = 4;
 
 		event.recipes.greate.pressing(ChemicalHelper.get(TagPrefix.gem, material, amount), ChemicalHelper.get(TagPrefix.block, material, 1))