As practiced by the Hse'eliae, GemArt is an extension of Faerie healing. In addition to the six major and six lesser stones, there are six Orbitals.  Before learning GemArt, a Hse'eliae must master Faerie Diagnosis, Faerie Healing and Gem Antidote skills.  He must also master Prospecting-Gems (M/A) and Gem Cutting (P/H).  GemArt is itself a (M/VH) skill which defines the different powers of each gem in each orbit.

NewSkill:  GemArt (M/VH)

This is the knowledge of the 12 orbits and which gems fit in which and what they can do therein. It does NOT convey the ability to use the power of the gems so placed. A GemArt skill is required to orbit a stone (that is, to launch it).  A GemMaster may orbit one stone per point of skill.

What it looks like:

GemMasters look a little strange - Elves with metallic gold skin surrounded by flashing gems whirling about their bodies in various orbits. A fully equipped GemMaster can keep as many as 12 gems going at once. The orbits are halo (over the head),  right face, left face, back face (back of the head), neck, shoulder, chest, back, right hand, left hand, abdomen/groin, and whole body spiral. When the hands are pressed against the body, handorbits swing in a figure eight as near to the hand as possible. The orbits are designed so that the stones can never intersect.  GemMasters most also carry on their person the Major and Minor stones, most often in six weirwood rings and a necklace with the gems set in weirwood clasps (having a bit of weirwood on the stones do not prevent them from working). Though GemMasters can wear metal and weirwood armor, they cannot have vitredur in their aura.

How it works:

Placing certain gems in certain orbits gives the GemMaster the power to cast a spell.  Each of these spells must be learned as a separate skill. For instance,  Tsi'ingdol Sundog knows the spell Purify Water.  He can cast the spell so long as he has an alexandrite in the Left Hand orbit. The fatigue cost and time to cast are as GURPS Magic (1pt per gallon, 5 seconds).  If he knows Ethereal Body, a more complex spell, he must have Topaz in his halo, Tourmaline in neck orbit, and Uvarovite in his chest orbit. Only one spell can occupy a single orbit at a time.

Prismitite Powerstones:

GemMasters CANNOT draw power from the High Metals, but they can use Prismitite to make powerstones. Prismitite is EXTREMELY rare, much more valuable than diamonds, and is found only in the Rainbow Flow deep in the Burning Desert. It is enchanted just as per the Powerstone spell, and can be used for extra fatigue. Prismitite must occupy the Body Spiral orbit.

Theft and Paranoia

Needless to say, GemMaster are a little paranoid about theft, considering the amount of valuables they carry on their persons. Orbiting stones are very hard to steal - anyone other than their possess who grasps one takes 2d damage and experiences a thuderclap and flash of light.  There is also a special spell, using Diopside in the Halo orbit,  which will cause a similar effect for any gemstone on the Master's person. GemShield is M/H, lasts 12 hours, 1 pt to cast, 1 to maintain, CT 10 seconds. Another common option is to take one of magical SecondSights, Especially Feel for Treachery
 

Major Stones:
Diamond - brillant transparent
Ruby - deep translucent red
Sapphire - deep transluscent blue
Aquamarine - translucent bluish green
Emerald - vibrant translucent grass green
Jet - transluscent lusterous black
 

Minor Stones:
Moonstone - clear in sunlight, glows milkly white in darkness
Sunstone - translucent yellow stone with inner orange light, produces some heat
Garnet -  pale translucent green
Amethyst - translucent pale purple
Tourmaline - translucent pink and gold
Opal - iridescent white with multicolored flakes
 

Orbital Stones:
Alexandrite - translucent, blue-green in sunlight, violet in artificial light
Topaz - translucent, pink and skyblue
Uvarovite - translucent gray-green
Scapolite -  translucent deep, rich purple
Diopside - translucent rich, forest green
Clinohumite - translucent yellow orange

Special Powerstone:
Prismitite - clear in darkness, held up to sun, radiates different color on each facet as turned