Maritime Quartz

When deep ocean currents converge from the four corners of the world, their meeting point is often host to an outcrop of Maritime Quartz. Harvested by enterprising merfolk, these prized constructs of salt and brine soon enter the hands of wizards who value their strange relationship with magic.
  Description: Maritime Quartz is a clear crystal that comes in a variety of shades of blue and green. Like many crystals, this material possesses a deep purity that allows it to channel magical power in an efficient manner. However, items made of maritime quartz are also suited to perform tasks of a less enigmatic nature.
  Natural Properties: An item made of maritime quartz that is being worn or held can function as an arcane focus for spells. Held Items. Holding an item made of maritime quartz does not prevent you from performing the somatic components of spells.
  Example Item: Maritime Quartz Sword. A weapon carved of maritime quartz allows a warrior versed in spellcraft to freely practice the Art on the field of battle.