While holding the mortar and pestle, you can use your action to say the name of any nonmagical plant, mineral, or fluid and an amount of the material worth 10 gp or less. The mortar instantly fills with the desired amount of that material. Once you use this action, you can't do so again until you finish a short or long rest.
You can also use the artifact as alchemist's supplies, brewer's supplies, cook's utensils, an herbalism kit, and a poisoner's kit. You have advantage on any check you make using the artifact as one of these tools.