A proppant composition may include at least about 50 wt% total silica and up to about 50 wt% total alumina and a connected porosity greater than or equal to about 5%, A proppant precursor composition may include an alumina- or aluminosilicate- containing material and diatomaceous earth, wherein the diatomaceous earth may be greater than or equal to about 25 wt%. A method of making a proppant may include mixing an alumina- or aluminosilicate-containing material and diatomaceous earth to form a precursor composition, pelletizing the precursor composition, and sintering the pelletized precursor composition to form a sintered proppant having a connected porosity greater than or equal to about 5%. A method of treating a fracture site may include delivering a sintered proppant including an active agent to a well site, and dispersing the active agent from the sintered proppant within the well site.