By roughly 200 BCE cut stone tesserae were being used in Hellenistic-Greek mosaics. Mosaics are images formed with small pieces of stone or glass, called "tesserae". The wide assortment of colored shades of glass tesserae further enhances the mosaics. Although ungrouted mosaics do exist, most have grout between the tesserae. The beard is made of carved lapis lazuli tesserae on a silver backing. It excludes glass and mosaic made from glass "tesserae". Roman opaque glass, possibly Roman glass tesserae. They sculpted artefacts that included fine tesserae and beads, to carved heads weighing . Ishtar Terra is also the site of many tesserae, formed by tectonic deformation. The glazed surfaces of the tesserae sparkled in the light and illuminated the basilica churches. A small area of red paving tesserae protected by railings marks the spot. The tiny "tesserae" allowed very fine detail, and an approach to the illusionism of painting. The tesserae are then lacquered and polished creating a durable and glossy surface. They are usually associated with "coronae" and "tesserae". It can provide areas of larger tesserae pieces for variety and contrast.