Growing interest in artisan and specialty cheeses has resulted in proliferation of cheeses that contain crystals. Until recently, many of these crystals were rarely encountered in the American marketplace. Crystals are natural products of ripening, and it is important to educate consumers about them so that artisan cheeses can be appreciated to the fullest. Powder X-ray diffractometry (PXRD) was used previously to identify crystals in several cheese varieties. Objectives of this research were (1) to identify crystals in cheeses that have not been studied previously using PXRD; and (2) to combine results from this and previous PXRD studies to develop a guide for cheesemakers, retailers, and consumers. Imported Emmental, Comté, Appenzeller, Sbrinz, Mimolette, Pecorino Sardo, Manchego, and Roquefort cheeses, and domestically produced blue mold cheese that displayed visible crystals were obtained from local sources. Crystals were harvested, prepped, and analyzed by PXRD using previously described methods. Dense, hard crystals embedded in the bodies of Emmental, Comté, and Sbrinz cheeses were identified as l-tyrosine. Sbrinz also contained embedded crystals of brushite (calcium phosphate dihydrate), and Emmental contained crystals of l-tyrosine and brushite that deposited prominently along the surfaces of eyes within the cheese. Appenzeller developed crystals of calcite (calcium carbonate), ikaite (calcium carbonate hexahydrate) and struvite (magnesium ammonium phosphate hexahydrate) in the smear at the rind surface. Mimolette contained profuse crystallization along the surface of internal eyes, which took the form of l-leucine sheets. Pecorino Sardo contained discrete internally visible crystals of d/l-calcium lactate pentahydrate, as well as traces of brushite. Manchego contained discrete internally visible crystals consisting of leucine along with brushite. Roquefort cheese contained visible internal crystals near regions where mold grew profusely, which consisted of l-tyrosine, l-leucine and brushite. Domestic blue mold cheese that displayed surface smear growth also contained crystals of ikaite and struvite in the surface smear. Results were compiled into a guide and classification scheme to aid in navigating the world of cheese crystals.