The invention provides separated calcium phosphate platelets with a length of between 250 nm and 800 nm. The invention also provides dispersions comprising the platelets according to the invention or colloidal dispersions obtained by resuspending the said platelets in the presence of a dispersing agent. The invention also relates to a process for preparing platelets according to the invention. Finally, another subject-matter of the invention is the use of the abovementioned platelets as reinforcing filler, polishing agent, building materials, additive for oral formulations, in particular dentifrices, or encapsulating agent.