Intaglio (jewellery) in the context of "Semi-precious"

Epigraphy (from Ancient Greek ἐπιγραφή (epigraphḗ) 'inscription') is the study of inscriptions, or epigraphs, as writing; it is the science of identifying graphemes, clarifying their meanings, classifying their uses according to dates and cultural contexts, and drawing conclusions about the writing and the writers. Specifically excluded from epigraphy are the historical significance of an epigraph as a document and the artistic value of a literary composition. A person using the methods of epigraphy is called an epigrapher or epigraphist. For example, the Behistun inscription is an official document of the Achaemenid Empire engraved on native rock at a location in Iran. Epigraphists are responsible for reconstructing, translating, and dating the trilingual inscription and finding any relevant circumstances. It is the work of historians, however, to determine and interpret the events recorded by the inscription as document. Often, epigraphy and history are competences practised by the same person. Epigraphy is a primary tool of archaeology when dealing with literate cultures. The US Library of Congress classifies epigraphy as one of the auxiliary sciences of history. Epigraphy also helps identify a forgery: epigraphic evidence formed part of the discussion concerning the James Ossuary.

An epigraph (not to be confused with epigram) is any sort of text, from a single grapheme (such as marks on a pot that abbreviate the name of the merchant who shipped commodities in the pot) to a lengthy document (such as a treatise, a work of literature, or a hagiographic inscription). Epigraphy overlaps other competences such as numismatics or palaeography. When compared to books, most inscriptions are short. The media and the forms of the graphemes are diverse: engravings in stone or metal, scratches on rock, impressions in wax, embossing on cast metal, cameo or intaglio on precious stones, painting on ceramic or in fresco. Typically the material is durable, but the durability might be an accident of circumstance, such as the baking of a clay tablet in a conflagration.

Cameo (/ˈkæmioʊ/) is a method of carving an object such as an engraved gem, item of jewellery or vessel. It nearly always features a raised (positive) relief image; contrast with intaglio, which has a negative image. Originally, and still in discussing historical work, cameo only referred to works where the relief image was of a contrasting colour to the background; this was achieved by carefully carving a piece of material with a flat plane where two contrasting colours met, removing all the first colour except for the image to leave a contrasting background.

A variation of a carved cameo is a cameo incrustation (or sulphide). An artist, usually an engraver, carves a small portrait, then makes a cast from the carving, from which a ceramic type cameo is produced. This is then encased in a glass object, often a paperweight. These are very difficult to make but were popular from the late 18th century through the end of the 19th century. Originating in Bohemia, the finest examples were made by the French glassworks in the early to mid-nineteenth century.