Gems¶
A gem is not mere wealth; its crystal lattice is ordered matter, which holds magic the way a vessel holds water. For magical rituals, a gem is fuel.
Size & Quality¶
A gem's value measures its size and purity and its capacity to hold magic. Values are 10, 50, 100, 500, 1,000, 5,000, 10,000, and 50,000 gp. These values are not necessarily measures of what the gem could be bought and sold for, but they do determine potency in magical crafting. Only a gem of 100 gp or greater can serve as a reagent in a magical craft; lesser stones are wealth and nothing more.
Hastening a Craft with Gems¶
When the rules for Crafting a Magic Item (including Spell Research) are used, one or more reagent gems may be used to hasten the work. Total the value of the gems used. Take that total as a percentage of the crafting cost; the crafting time is reduced by that percentage, to a maximum of 50%. The gems are consumed during the process.
Example. Rare item (2,000 gp, 5 weeks). A 1,000 gp gem halves the work to 2.5 weeks. So does a 500 gp emerald if the item is conjuration-based.
Affinity¶
Every reagent gem can fuel any magic, but each resonates most strongly with a single school, shown by its color. When a gem is used as a reagent of its affiliated school, it counts as twice its value. Diamonds and other colorless stones have no single affinity and always count as twice their value.
| Color | School | Example stones |
|---|---|---|
| Red | Evocation | carnelian, garnet, ruby |
| Orange / Yellow | Transmutation | citrine, amber, fire opal |
| Violet | Illusion | amethyst |
| Rose / Pink | Enchantment | rose quartz, pink tourmaline, pink diamond |
| Blue | Abjuration | lapis lazuli, aquamarine, sapphire |
| Green | Conjuration | malachite, jade, peridot, emerald |
| Iridescent | Divination | moonstone, opal, black opal |
| Black | Necromancy | obsidian, onyx, black pearl |
| Colorless | Any (universal) | clear diamond |
Buying and Selling Gems¶
A gem may usually be sold for its normal value, but buying a gem is more difficult. Small stones may be found in a city's markets, but reagent-quality gems, and those of 5,000 gp or more, are bought rarely, at a premium, and never on demand.