The invention relates to faceted gemstones based on a luminescent glass composition that contains particular oxides of rare earth metals and thus enables the faceted gemstones to be identified, and to a process for identifying the gemstones.

Glass ceramic material for the production of synthetic stones in fashion jewellery and jewellery, having excellent mechanical properties, chemical and heat resistance, harmless due to absence of lead, arsenic and cadmium compounds, available in a broad scale of colour designs, imitating faithfully natural precious stones thanks to high content of spinel crystalline phase and lowered content of SiO.sub.2, consisting of (in weight %): 20-40% SiO.sub.2, 1.5-10% B.sub.2O.sub.3, 20-35% Al.sub.2O.sub.3, 0.1-20% MgO, 0.1-20% ZnO, the content of MgO+ZnO being at least 10%, preferably also 0-15% TiO.sub.2, 0.1-15% ZrO.sub.2, the content of TiO.sub.2+ZrO.sub.2 being at least 5%, more preferably also 0-20% of colouring additives in the form of CoO, NiO, CuO, Fe.sub.2O.sub.3, MnO.sub.2, Cr.sub.2O.sub.3, V.sub.2O.sub.5, Pr.sub.2O.sub.3, CeO.sub.2, Nd.sub.2O.sub.3, Er.sub.2O.sub.3, AgO and Au.

The invention relates to a decorative element comprising an elongate support body and a multitude of, in particular faceted, gemstones on an adhesive layer on the support body, wherein a minimum position and a maximum position exist for each of the gemstones.

Proposed is a decorative element containing (a) a gemstone, (b) an electrically conductive layer on at least a partial area of the gemstone; and (c) an electronic sensor.

The invention relates to a decorative ornamental element containing a transparent plano-convex gemstone, a wavelength-selective layer and a color-changeable seating surface, thus being able to cause aesthetic effects and signal effects by color changes. The ornamental element is characterized by a high brilliance and decorative color effect.

The invention relates to faceted gemstones based on a luminescent glass composition that contains particular oxides of rare earth metals and thus enables the faceted gemstones to be identified, and to a process for identifying the gemstones.

The invention relates to a method for partially coating a surface of an object, comprising the following steps: (a) optional hydrophobization of the surface of the object; (b) partial application of (b1) a liquid and subsequent application of a powderous or granular substance or (b2) a solution or suspension of said powderous or granular substance in a liquid; (c) drying the surface to form spatially-delimited salt or powder crusts; (d) coating the surface with at least one layer of a metal or a metal compound; and (e) removing the salt or powder crusts that have been produced. The invention also relates to products that have been produced according to the claimed method.

A decorative glass article contains: in mol %, 10% to 70% of La.sub.2O.sub.3, 10% to 90% of Nb.sub.2O.sub.5, 0% to 40% of B.sub.2O.sub.3, and 0% to 50% of TiO.sub.2, wherein a refractive index is 2.0 or more and an Abbe number is 50 or less.

A glass article contains: in mol %, more than 0% to 70% of La.sub.2O.sub.3, 0% to 80% of B.sub.2O.sub.3, 0% to 40% of SiO.sub.2, 0% to 80% of B.sub.2O.sub.3+Al.sub.2O.sub.3+SiO.sub.2, 0% to 85% of Gd.sub.2O.sub.3+Ga.sub.2O.sub.3+Y.sub.2O.sub.3+Yb.sub.2O.sub.3+ZrO.sub.2+TiO.sub.2+Nb.sub.2O.sub.5+Ta.sub.2O.sub.5+WO.sub.3, 0% to 15% of MgO+CaO+SrO+BaO, 0% to 35% of ZnO, and more than 0% to 5% of CuO.

Provided is a jewelry display system including a display device for storing a plurality of clear display cards. Each of the plurality of display cards displays or includes a plurality of precious stones in order of progressively increasing carat weight or size. Each display card includes a respective cut of precious stone so that a user may use the display cards to view precious stones of different cuts, carat weights, and sizes over the top of the user's ring finger. The display cards may further include magnets to removably couple the display cards within the display device.