Book excerpt: The investigation of key mineral phases such as zircon, apatite, titanite, rutile, monazite, xenotime, allanite, baddeleyite and garnet, explored in this book, has provided breakthroughs in our understanding of continental crust composition and evolution, as well as the timing, conditions, petrogenetic and geodynamic processes related to its growth and reworking. Therefore, the continuing development of analytical techniques, improvement of tools, data handling, processing, and interpretation allow us to extract and better understand these complex geological processes. This special publication aims at showcasing contributions reviewing the tools and applications of these key minerals, recent technique developments, and new applications using focused case studies investigating igneous, metamorphic and/or detrital rocks that help us put together the continental crust evolution puzzle. This volume highlights the progress made in studies using these key minerals and their future potential.