Elvish Engineering: Powerstones

Another new article series? Madness! I was all prepared to alternate Cities and Factions articles for a couple months when I realized there are some key pieces of tech that are essential to the purposes of certain cities or factions. So I'm going to sprinkle these tech articles into the mix as needed to make later articles make sense. Spoiler: next week's article will involve powerstones, so I'm explaining them now.

Announcements done. Where was I?

Powerstones

Description

A powerstone is a lump of crystal imbued with magical energy. This can be raw, undifferentiated power but more often is a specific spell. Sometimes crystals that don't contain any magic are still called powerstones because they are intended for that purpose. The amount of magic that can be contained is proportional to the quality of the crystal and its size. For example, a very large milky quartz has about the same capacity as a small flawless diamond. Cut doesn't really matter beyond physical size so powerstones are often shaped for a specific purpose.

The most common powerstones are made of rough-cut quartz and are about the size of a fist. Amethyst is another common material. Corundums such as ruby and sapphire are less common. Diamond powerstones are extremely rare. Size naturally decreases with rarity.

Usage

Cracking or shattering a powerstone immediately triggers the spell or releases the raw energy stored within. Raw energy released in this way escapes in a big explosion.

There are three common uses for powerstones:

• The smallest powerstones are used to store spells within jewelery and clothing (this is not the same as Spell Storing items and weapon enhancements). The setting will have a mechanism to crack the crystal and release the spell.
• Medium powerstones are commonly used as weapons by imbuing them with raw energy and intentionally breaking them on enemies. 
• The largest powerstones are used to bind elementals in the cores of airships for propulsion (Airships will get a full article on March 6th).

Powerstones can be used as artillery shells. A smoothly-ground spherical or columnar powerstone be clad in a metal casing and fired from a cannon with some accuracy. The casing cracks the stone on impact with the target. Powerstones used in this way usually have raw magical energy imbued into them but sometimes specific spells are used (such as to create a smoke screen or release poison gas).

Creation

Any crystal or gemstone can be used to create a powerstone. Gems worth 50gp or less can store a 2nd-level spell. The required gp value doubles for each additional spell level; a gem that is large and valuable enough to hold a 9th-level spell would be worth 65,000gp. No such gems are known to exist.

Unlike scrolls, a spell released from a powerstone retains the caster level of its creator. No skill is needed to activate a powerstone. In fact, they must be handled with care to prevent accidental (explosive) breakage.

Next Week

Next week's article will be a Cities article about the dwarven city Kor's Geode, Ashdar. Kor's Geode is a prominent source of raw crystals used in powerstone production.