Petraglifs are the lifeblood of gome society. Petraglifs give gomes health and power. In Twilight Cave, Wullie describes it well to Hadley and Alina in a bedroom in Segovia:
“Humans have always had a fascination wi’ rocks. They like to collect them. They cut and polish the prettiest ones and wear them as jewelry. They carve others into sculptures so they can admire them. It must be the permanence of rocks that they like. Rocks last forever, or at least for a lot longer than human lives, so humans keep them, and grow fond of them and pass some of them on tae the next generation. And of course yoose have learned tae make things out o’ rocks, too; cups, plates, bowls and the like. Gomes are always on the lookout for rocks that have special significance tae humans. We call them petraglifs. Rocks that humans especially like absorb life and emotion into them so that they have healing power. If gomes grind them up intae powder and potions, or chew them up, they help us tae repair ourselves when bits of us get chipped or knocked off. Have you ever noticed that it is always your favorite plate or cookie jar that gets broken, or your mom’s favorite vase that falls off the window sill? That’s not a coincidence. That’s the work of gomes, moving them when you’re no’ looking, setting things in position so they might get knocked off and broken. Then the gomes sneak back during the night and collect some of the pieces as petraglifs.”
Petraglifs vary in their strength and in the type of power they have. The larger the number of humans that make a connection with a rock and the longer that association lasts the more powerful it becomes as a petraglif. One child’s favorite mug will contain a small amount of happiness and comfort. But a sculpture that has been admired by thousands of tourists for decades on end will contain a much larger amount of emotions. The emotional power of this petraglif will also be more complicated. When a sculpture is first carved it may produce shock and ridicule among some humans but over time more and more may learn to enjoy it, be inspired by it and so it may grow to contain lots of awe, admiration, shock, and even envy. Some petraglifs contain less happy emotions. The gravestone of a much loved relative will become full of sadness and nostalgia as family members visit the grave, touch the stone and think of their loved one. A chunk of prison wall would be full of anger, fear, and regret. Certain gomes spend centuries of training to become very skilled at identifying the specific power of petraglifs. These gomes are sometimes thought of as magicians or wizards, but are also called Translators because they have the skill to translate the particular power that the petraglif contains into useful powders or potions. We meet Catalysmo-The-Great-Translator on Level Four of the gome city of Barcelunda. Jade-Tsi-Dong is an even more powerful Translator. In his secluded workshop in Barcelunda’s Chinatown we see him Divining the essence of a petraglif. He grinds it up to gravel and powder and then sprinkles that powder into a dozen other bowls containing mysterious liquids that can identify properties of the petraglif.
The dust and gravel from different petraglifs can be combined, along with spices and herbs. As Jade-Tsi-Dong explains to Alina:
Spices help to bind the emotions together; ginger root, lemon grass, cinnamon bark, tea tree oil. These help to pull the emotions out, and push them forward to a new purpose.
Some petraglifs can be used to help gomes to heal from injuries. Others are used to make potions to increase their power or to weaken their enemies.