Glass is a non-crystalline amorphous solid that is often transparent and has widespread practical, technological, and decorative usage. Glass was used extensively during the Middle Ages. Anglo-Saxon glass has been found across England during archaeological excavations of both settlement and cemetery sites. Glass in the Anglo-Saxon period was used in the manufacture of a range of objects including vessels, beads, and windows, and was also used in jewelry.
Turquoise is an opaque, blue-to-green mineral that is a hydrated phosphate of copper and aluminum. It is rare and valuable in finer grades and has been prized as a gem and ornamental stone for thousands of years owing to its unique hue. The finest of turquoise reaches a maximum hardness of just under 6, or slightly more than window glass. The luster of turquoise is typically waxy to sub vitreous, and transparency is usually opaque, but may be semi translucent in thin sections. Color is as variable as the mineral's other properties, ranging from white to a powder blue to a sky blue, and from a blue-green to a yellowish green.