Gemstones in the context of "Opal"

Jewellery (or jewelry in American English) consists of decorative items worn for personal adornment such as brooches, rings, necklaces, earrings, pendants, bracelets, and cufflinks. Jewellery may be attached to the body or the clothes. From a Western perspective, the term is restricted to durable ornaments, excluding flowers for example. For many centuries, metals such as gold and silver, often combined with gemstones, has been the normal material for jewellery. Other materials such as glass, shells, or wood may also be used.

Jewellery is one of the oldest types of archaeological artefact – with 100,000-year-old beads made from Nassarius shells thought to be the oldest known jewellery. The basic forms of jewellery vary between cultures but are often extremely long-lived; in European cultures the most common forms of jewellery listed above have persisted since ancient times, while other forms such as adornments for the nose or ankle, important in other cultures, are much less common.

In Greek mythology, Theia (/ˈθiːə/; Ancient Greek: Θεία, romanized: Theía, lit. 'divine') also called Thea, Thia, Euryphaessa, Aethra or Basileia, was one of the Titans, the children of Uranus (Sky) and Gaia (Earth). She is the goddess of minerals and gemstones.

Her brother-husband is Hyperion, a god of the light, and together they are the parents of Helios (the Sun), Selene (the Moon), and Eos (the Dawn). She seems to be the same figure as Aethra, who is the wife of Hyperion and mother of his children in some accounts. Like her husband, Theia features scarcely in myth, being mostly important for the children she bore, though she appears in some texts and rare traditions.

In Australia, New Zealand and Cornwall, fossicking is prospecting, especially when carried out as a recreational activity. This can be for gold, precious stones, fossils, etc. by sifting through a prospective area. In Australian English and New Zealand English, the term has an extended use meaning to "rummage". Though the term has been argued to come from Cornish, it likely originates from the Latin fossa, meaning “ditch”, “trench”.

In Australia, "fossicking" is protected by a number of laws, which vary from state to state. In Queensland, fossickers must obtain a licence, but no licence is required in New South Wales. In South Australia, fossicking is defined as "the gathering of minerals as (a) a recreation; and (b) without any intention to sell the minerals or to utilise them for a commercial purpose", and these activities are considered as not being affected by the Mining Act.

Beryllium is a chemical element; it has symbol Be and atomic number 4. It is a steel-gray, hard, strong, lightweight and brittle alkaline earth metal. It is a divalent element that occurs naturally only in combination with other elements to form minerals. Gemstones high in beryllium include beryl (aquamarine, emerald, red beryl) and chrysoberyl. It is a relatively rare element in the universe, usually occurring as a product of the spallation of larger atomic nuclei that have collided with cosmic rays. Within the cores of stars, beryllium is depleted as it is fused into heavier elements. Beryllium constitutes about 0.0004 percent by mass of Earth's crust. The world's annual beryllium production of 220 tons is usually manufactured by extraction from the mineral beryl, a difficult process because beryllium bonds strongly to oxygen.

In structural applications, the combination of high flexural rigidity, thermal stability, thermal conductivity and low density (1.85 times that of water) make beryllium a desirable aerospace material for aircraft components, missiles, spacecraft, and satellites. Because of its low density and atomic mass, beryllium is relatively transparent to X-rays and other forms of ionizing radiation; therefore, it is the most common window material for X-ray equipment and components of particle detectors. When added as an alloying element to aluminium, copper (notably the alloy beryllium copper), iron, or nickel, beryllium improves many physical properties. For example, tools and components made of beryllium copper alloys are strong and hard and do not create sparks when they strike a steel surface. In air, the surface of beryllium oxidizes readily at room temperature to form a passivation layer 1–10 nm thick that protects it from further oxidation and corrosion. The metal oxidizes in bulk (beyond the passivation layer) when heated above 500 °C (932 °F), and burns brilliantly when heated to about 2,500 °C (4,530 °F).

Cameo glass is a luxury form of glass art produced by cameo glass engraving or etching and carving through fused layers of differently colored glass to produce designs, usually with white opaque glass figures and motifs on a dark-colored background. The technique is first seen in ancient Roman art of about 30 BC, where it was an alternative to the more luxurious engraved gem vessels in cameo style that used naturally layered semi-precious gemstones such as onyx and agate. Glass allowed consistent and predictable colored layers, even for round objects.

From the mid-19th century there was a revival of cameo glass, suited equally to Neo-Grec taste and the French Art Nouveau practiced by Émile Gallé. Cameo glass is still produced today.