A Guide to Rocks is a deliberately elementary introduction to earth magic, written for readers who cannot yet be trusted with anything more dangerous than a pebble. Its premise is that a mage hoping to command stone should first be able to recognise the material in front of them. The author therefore postpones most actual spellcraft until the reader has learned what a rock is, why one rock is not necessarily the same as another, and why pointing at both while saying “stone” is insufficient. The result is useful, methodical and far more about rocks than anyone reasonably expects.
What the Book Teaches
The opening chapters define stone, rock, mineral, soil and gravel, then spend an impressive number of pages explaining why these terms should not be used interchangeably. Rocks are sorted by colour, grain, hardness, density, fracture and likely origin. The text explains how water, heat, pressure and weather alter them, and how to distinguish a natural surface from one that has been cut, polished or worked. A short section on smooth grey stones concedes that many of them are, regrettably, smooth and grey.
The catalogue that follows covers common stones found across Orth. Each entry describes weight, texture, usual surroundings and the sound produced when struck against another specimen. Small ink diagrams accompany the text. These are technically accurate, but several look sufficiently alike that the captions do most of the work. Readers are repeatedly advised to examine a stone in good light, turn it over before reaching a conclusion and avoid identifying anything solely because it resembles the example on the previous page.
Several chapters deal with practical errors. Dirt can conceal colour, polished surfaces can disguise grain, and a wet rock may look more interesting than it truly is. The book also warns against tasting unknown minerals, carrying unstable crystals loose in a pocket or assuming that every unusually warm stone is magical. Sometimes, it explains, a rock has simply been sitting in the sun.
The Earth Magic
Actual earth magic begins roughly halfway through the volume. The first exercises ask the reader to hold a pebble, note its weight and remain still long enough to sense the difference between the object and the ground beneath it. Later exercises cover recognising worked stone by touch, following a seam through a larger piece and detecting the faint residue left when magic has recently altered rock. These lessons are presented with great seriousness and very little expectation of immediate success.
The book never advances to raising walls, opening chasms or throwing boulders. Such work is described as “material for later study”, after the reader has demonstrated that they can tell sandstone from granite without assistance. The most ambitious exercise moves loose grit across a tabletop. Even this is preceded by six pages on choosing suitable grit, two pages on arranging it and a firm warning not to practise near food.
Exercises and Assessment
Most practical work consists of sorting trays of samples. Early exercises use labelled stones; later ones remove the labels and expect the reader to rely on observation. The recommended method is to compare colour, grain, weight and hardness, record the result, then check the answer before becoming attached to it. Guessing is discouraged, as is inventing a new category because none of the available answers feels quite right.
The final assessment presents a dozen ordinary rocks and asks the reader to identify them, explain the signs used and state whether each would be suitable for basic earth magic. Several specimens are deliberately similar. One is not a rock at all. The book treats this as a fair test of attention rather than a trick, although generations of readers have disagreed.
Use and Reputation
For all the mockery it attracts, the guide is not useless. Masons, miners, travellers and novice earth mages can all benefit from recognising common stone, damaged masonry and unstable ground. What it does not provide is power. A reader may finish with a respectable grasp of rocks and no meaningful ability to command them, which is less impressive than the title first suggests but considerably safer.
A copy is kept in The Grand Library. The book acquired an unlikely reputation during A Short Month, when its absurdly narrow expertise proved memorable. Reading it grants proficiency in identifying rocks. It grants no equivalent proficiency in earth magic, geology as a whole, finding valuable gems or persuading anyone else that this was a worthwhile use of an afternoon.