Ruby of the War Mage

{w}Requires attunement
Etched with eldritch runes, this 1-inch-diameter
ruby allows you to use a simple or martial
weapon as a spellcasting focus for your spells.
For this property to work, you must attach the
ruby to the weapon by pressing the ruby against
it for at least 10 minutes. Thereafter, the
ruby cannot be removed unless you detach it as
an action or the weapon is destroyed. Not even
an antimagic field causes it to fall off. The
ruby does...(See Handout For Full Description)