Debris disks provide exciting opportunities to study planet formation throughout the disk. In exoplanetary debris disks, little is known about whether differentiated (crust and mantle) planetesimals are common in regions close to a star. If a debris disk contains crustal materials, indicating the existence of differentiated planetesimals, then we can understand its planetary evolution stage. The processes in which a star affects its debris disks are also largely unknown. A fundamental question is whether the stello-centric distance to the edge of icy belts, such as the Kuiper belt, is affected by its host star luminosity. The most comprehensive, homogeneous debris disk catalog to-date, the Spitzer IRS debris disk catalog, provides unique laboratories for studying these questions. I will identify the crust-like and mantle-like dust contents in the extrasolar debris disks in the Spitzer IRS debris disk catalog, and investigate the dust properties as a function of the stellar properties, using a non-parametric, systematic tool called Sequencer. The identification and characterization of the mineralogy of the debris disks will provide well-motivated candidates for future JWST studies on planetary evolutions.