A carrier for a catalyst for the epoxidation of an olefin wherein the carrier: (a) comprises at least 80 percent by weight alumina, and of that alumina, at least 90 percent is alpha-alumina, exclusive of modifier; (b) has a surface area of at least 1.0 m 2 /g, as determined by the BET method by nitrogen as described in the Journal of the American Chemical Society 60 pp.309-316; and (c) either has a porosity of at least 75 percent; and an average flat plate crush strength of at least 1 lb/mm (0.45 kg/mm), measured as a hollow cylinder having an axial cylindrical opening along the length of the cylinder, an outer diameter of 0.26 inches (0.660 cm) and an inner diameter of the opening of 0.1 inches (0.254 cm) and a length of 0.25 inches (0.635 cm); said porosity and average flat plate crush strength each being measured by the method described in the description; or has a porosity of at least 70 percent and an average flat plate crush strength of at least 3.5 lb/mm (1.6 kg/mm), measured as a hollow cylinder having an axial cylindrical opening along the length of the cylinder, an outer diameter of 0.26 inches (0.660 cm) and an inner diameter of the opening of 0.1 inches (0.254 cm) and a length of 0.25 inches (0.635 cm); said porosity and average flat plate crush strength each being measured by the method described in the description; and further wherein the alpha-alumina in the carrier comprises platelets, said platelets comprising either (i) 1 to 20 atom percent silicon measured as the element silicon in the first one to 50 atomic layers by x-ray photo-electron spectroscopy, said x-ray photo-electron spectroscopy being measured by the method described in the description; or (ii) 1 to 20 atom percent boron measured as the element boron in the first one to 50 atomic layers by x-ray photo-electron spectroscopy, said x-ray photo-electron spectroscopy being measured by the method described in the description;. (a) comprises at least 80 percent by weight alumina, and of that alumina, at least 90 percent is alpha-alumina, exclusive of modifier; (b) has a surface area of at least 1.0 m 2 /g, as determined by the BET method by nitrogen as described in the Journal of the American Chemical Society 60 pp.309-316; and (c) either has a porosity of at least 75 percent; and an average flat plate crush strength of at least 1 lb/mm (0.45 kg/mm), measured as a hollow cylinder having an axial cylindrical opening along the length of the cylinder, an outer diameter of 0.26 inches (0.660 cm) and an inner diameter of the opening of 0.1 inches (0.254 cm) and a length of 0.25 inches (0.635 cm); said porosity and average flat plate crush strength each being measured by the method described in the description; or has a porosity of at least 70 percent and an average flat plate crush strength of at least 3.5 lb/mm (1.6 kg/mm), measured as a hollow cylinder having an axial cylindrical opening along the length of the cylinder, an outer diameter of 0.26 inches (0.660 cm) and an inner diameter of the opening of 0.1 inches (0.254 cm) and a length of 0.25 inches (0.635 cm); said porosity and average flat plate crush strength each being measured by the method described in the description; and further wherein the alpha-alumina in the carrier comprises platelets, said platelets comprising either (i) 1 to 20 atom percent silicon measured as the element silicon in the first one to 50 atomic layers by x-ray photo-electron spectroscopy, said x-ray photo-electron spectroscopy being measured by the method described in the description; or (ii) 1 to 20 atom percent boron measured as the element boron in the first one to 50 atomic layers by x-ray photo-electron spectroscopy, said x-ray photo-electron spectroscopy being measured by the method described in the description;. (i) 1 to 20 atom percent silicon measured as the element silicon in the first one to 50 atomic layers by x-ray photo-electron spectroscopy, said x-ray photo-electron spectroscopy being measured by the method described in the description; or (ii) 1 to 20 atom percent boron measured as the element boron in the first one to 50 atomic layers by x-ray photo-electron spectroscopy, said x-ray photo-electron spectroscopy being measured by the method described in the description;.