Hardstone carving

Hardstone carving is a general term in art history and archaeology for the artistic carving of predominantly semi-precious stones (but also of gemstones), such as jade, rock crystal (clear quartz), agate, onyx, jasper, serpentine, or carnelian, and for an object made in this way. Normally the objects are small, and the category overlaps with both jewellery and sculpture. Hardstone carving is sometimes referred to by the Italian term pietre dure; however, pietre dura (with an "a") is the common term used for stone inlay work, which causes some confusion.

From the Neolithic period until about the 19th century such objects were among the most highly prized in a wide variety of cultures, often attributed special powers or religious significance, but today coverage in non-specialist art history tends to be relegated to a catch-all decorative arts or "minor arts" category. The types of objects carved have included those with ritual or religious purposes, engraved gems as signet rings and other kinds of seal, handles, belt hooks and similar items, vessels and purely decorative objects.

Hardstone carving falls under the general category of glyptic art, which covers small carvings and sculpture in all categories of stone. The definition in this context of "hardstone" is unscientific and not very rigid, but excludes "soft" stones such as soapstone (steatite) and minerals such as alabaster, both widely used for carving, as well as typical stones for building and monumental sculpture, such as marble and other types of limestone, and sandstone. These are typically not capable of a fine finish in very small carvings, and would wear in prolonged use. In other contexts, such as architecture, "hard stone" and "soft stone" have different meanings, referring to actual measured hardness using the Mohs scale of mineral hardness and other measures. Some rocks used in architecture and monumental sculpture, such as granite, are at least as hard as the gemstones, and others such as malachite are relatively soft but counted as hardstones because of their rarity and fine colour.

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