Final answer:
Rocks change from one form to another through processes such as cooling and crystallization for igneous rocks, cementation for sedimentary rocks, and intense heat and pressure for metamorphic rocks. These transformations are part of the rock cycle and lead to new rocks with distinct mineral content and textures.
Step-by-step explanation:
How Rocks Change Form
Rocks undergo transformations between three main types: igneous, sedimentary, and metamorphic rocks. Igneous rocks are created when magma cools and crystallizes. When pieces of other rocks or minerals cement together after weathering and erosion, they form sedimentary rocks. But a significant transformation occurs during metamorphism, where pre-existing rocks are altered by intense heat and pressure, changing their mineral content and structure, and leading to new metamorphic formations without melting. Factors like temperature and pressure increase with depth beneath the Earth's surface, mostly affecting rocks found in or near mountain ranges due to tectonic activities.
Changes in the physical and chemical conditions to which a rock is subjected often result in recrystallization, foliation, or complete mineralogical transformation, with the outcome being a metamorphic rock unique in mineral content and textural patterns. These processes complete the rock cycle by altering igneous, sedimentary, or even other metamorphic rocks.
For example, limestone can be transformed into marble, and shale can become slate through metamorphism. The degree of these changes and the resultant rock type are dependent on the original rock's composition, the level of heat, the pressure exerted, and the duration of these conditions.