Gemstone

Properties

Material Characteristics

It can be any type of ordinary stone that has shifted from it's normal appearance.  It can be any number of colors, sometimes multiple at a time, and is oil-slick to the touch.  
Very old gemstone is rumored to grow actual crystals that hold a vast amount of magical potential and make for excellent foci.  The chances of finding such a thing are exceedingly rare.

Physical & Chemical Properties

The stone is warm to the touch and is well known for the 'static shock' it generates, often giving out tiny zings of electric energy to anyone holding it.

Geology & Geography

Gemstone can form in any location that has had exceeding amounts of magical discharge.  This is most common in the Weirwood, but can be found throughout Liyr'a.

Origin & Source

Gemstone is formed from any common type of stone that has been exposed to large amounts of magic and left to soak it in over time.

Life & Expiration

If the stone is removed from the source of magic that formed it it will retain it's current degree of magical properties, if it is exposed to more magic it has the potential to keep growing depending on the strength and consistency of exposure.

History & Usage

History

Elves have used gemstone for centuries, it is used in their architecture for aesthetic, and is a common component in many of their magical practices.

Discovery

This type of stone was discovered many thousands of years ago in a marble quary.  There had been a magical ritual performed in the location (because of the isolation and large amount of space and lack of creatures and plant life that a missspell could endanger, quaries were used quite often for such purposes).  
The elf who discovered it became quite famous and became a household name in magical circles.  He opened up a shop selling the stone, and other foci, and quickly became exceedingly popular amongst mages of all sorts.  His decedents still operate the shop (and a few others) and are the most prestigious source for foci in the elven kingdoms. The Gemstone Foci Emporium

Type

Ore/Mineral

Color

can be found in a wide range of colors