Magic runestones are small stone plates that are infused with magical power. They are the result of a collaboration of elementals and wizards. They are normally found on the material plane or in the elemental planes. If you use an action to activate the runestone by putting it in your hand and speak the command word, it produces a magical effect that varies depending on the type of rune. 

This rune is made on a grey, metallic plate. If you activate it, you conjure 2 animated armor and 2 flying swords that lasts up to 1 hour (no action required to dismiss them). You also gain proficiency with smith tools and have advantage to determinate the price of an object made by an blacksmith. Once it has been used, you can't use it again until 2 days have passed.