An aspect of the invention relates to a process for manufacturing a horological or jewellery external part element, including a body made of hard material, inlaid with a decoration made of a second material, where in a first step the body made of the hard material is formed, during this first step or in a second step, a hollow is produced in a face of the body, in a third step, the surface condition of the bottom and/or walls of said hollow is modified to increase the contact area thereof, in a fourth step, this hollow is filled with the second material is a composite material including at least one bio-sourced charged polymer including at least one bio-sourced charged polymer chosen for the wear resistance thereof, to constitute an insert forming a said decoration, in a fifth step, a surface finishing of said insert is performed.

A method for rendering a gemstone traceable, includes the steps: providing an invisible marker, wherein the marker is unambiguously identifiable, fastening the marker in a placement location of the gemstone, and acquiring marking information that includes that this unambiguously identifiable marker is fastened to this gemstone. The marker can be transported to the placement location in a manner in which it is suspended in a carrier fluid. An additive, for example a primer or a starting material for a surface coating of at least a part surface of the placement location, can be added to the carrier fluid.

Methods of temporarily enhancing the luster and/or brilliance of a piece of jewelry, a gem stone, or a piece of jewelry including a gem stone including applying a non-aqueous composition to the piece of jewelry, the gem stone, or the piece of jewelry including a gem stone.

An exterior element for portable objects including a support, on which is arranged a first material, the first material being chosen to be capable of reflecting different visible wavelengths as a function of applied stress.

In an under component having a proximal end and a distal end, the under component comprising a cylindrical portion extending from the proximal end to the distal end; wherein the proximal end includes a rim that extends laterally from the cylindrical portion and that is flush with the proximal end; the rim extending from the cylindrical portion, wherein the rim includes a proximal edge and a distal edge. An over component having a proximal end and a distal end and a rim having a proximal edge and a distal edge, wherein the distal end of the under component extending to a position flush with a proximal edge of the rim of the over component, wherein the distal end of the over component extending to a position flush with a distal edge of the rim of the under component. A central component, wherein the central component is coupled to the over component, and the over component is coupled to the under component

Method for coloured coating on a watchmaking or jewellery external part component, comprising at least one visible surface prepared in advance on a substrate, this method comprising a step of vacuum-deposition of at least one main layer of titanium and silicon nitride (Ti, Si.sub.k)N.sub.x or of titanium and silicon nitride doped with oxygen (Ti, Si.sub.k)N.sub.xO.sub.y.

A substrate includes a final silver-plated surface protected against silver tarnishing by a protective coat having a thickness between 1 nm and 200 nm, the protective coat includes a first coat of Al.sub.2O.sub.3 deposited on said final silver-plated surface and having a thickness between 0.5 nm and 100 nm, and on the first coat of Al.sub.2O.sub.3, a second coat of TiO.sub.2 having a thickness between 0.5 nm and 100 nm, the substrate including a coat of a silver and copper alloy comprising between 0.1% and 10% by weight of copper with respect to the total weight of the alloy, forming said final silver-plated surface, said coat of a silver and copper alloy having a thickness between 1000 nm and 3000 nm. Embodiments also relate to a method for manufacturing such a substrate.

Methods of temporarily enhancing the luster and/or brilliance of a piece of jewelry, a gem stone, or a piece of jewelry including a gem stone including applying a non-aqueous composition to the piece of jewelry, the gem stone, or the piece of jewelry including a gem stone.

A piece of jewellery, wherein the jewellery comprises at least one tag or chip programmed with at least a unique identification code, and a tag reader is configured to read the tag or chip when the tag reader and the piece of jewellery touch, or come into close contact and, display a message or content associated with the unique identification code.

A piece of jewellery, wherein the jewellery comprises at least one tag or chip programmed with at least a unique identification code, and a tag reader is configured to read the tag or chip when the tag reader and the piece of jewellery touch, or come into close contact and, display a message or content associated with the unique identification code.