gothic: a style of architecture developed in northern France that spread throughout Europe between the 12th and 16th centuries; characterized by slender vertical piers and counterbalancing buttresses and by vaulting and pointed arches
architectural style: architecture as a kind of art form
powder photography: a process for identifying minerals or crystals; a small rod is coated with a powdered form of the substance and subjected to suitably modified X-rays; the pattern of diffracted rings is used for identification