Geomancers are one of the 4 major branches of elemental wizardry, alongside Pyromancers, Hydromancers, and Aeromancers. Geomancers, contrary to wizardly stereotypes, are solid as a rock, and often more happy on the front lines than hanging back. Their magic protects them from harm even as it crushes their foes. Earth magic is not especially subtle, but none can deny its power.
When you select this archetype at 2nd level, you gain the mage armor spell if you do not already have it, it is always prepared, and it does not count against your number of spells prepared. When you cast mage armor, you gain a +1 bonus to your AC.
Also at 2nd level whenever you make a melee spell attack or an unarmed strike while under the effects of a spell that improves them, you gain an expertise die on the attack roll.
At 6th level when you deal damage with an attack or spell that benefits from your Crushing Boulder ability, you deal additional magical bludgeoning damage equal to your Intelligence modifier.
At 10th level, you learn the stoneskin spell and add it to your spellbook if you do not already have it. You always have it prepared and it doesn't count against your number of spells prepared. You do not require concentration when casting stoneskin on yourself, and while under the effects of a stoneskin spell you cast you gain a +1 bonus to AC and an expertise die on Strength, Dexterity, and Constitution saving throws.
At 14th level all damage you deal with spells deals double damage to objects. In addition, your insight into earth magic deepens. You learn the earth barrier, stone shape, meld into stone, and wall of stone spells if you do not already know them and add them to your spellbook. These all count as wizard spells for you even if they are not normally on the wizard spell list. You may choose one of these spells to prepare that does not count against your normal number of spells prepared. At level 15 you also add the earthquake spell to this list of spells.