Abstract: Timepiece or jewelry part manufactured in an alloy containing at least 75% gold by weight, from 21% to 23% copper by weight, and from 1% to 4% platinum by weight.

Abstract: Timepiece or jewelry part manufactured in an alloy comprising at least 75% gold and between 15% and 18% copper or at least 18% copper, by weight. According to the invention, the alloy also comprises between 0.5% and 4% platinum with the exclusion of the 0.5% content when the copper content is equal to 15%. Preferably, the weight content of copper is between 20% and 22% for a weight content of platinum between 1.5% and 3%.

Abstract: This self-compensating spiral spring for a mechanical balance-spiral spring oscillator for a watch or clock movement or other precision instrument, made of an Nb—Hf paramagnetic alloy possessing a thermal coefficient of Young's modulus (TCE), such that it enables the following expression to be substantially equal to zero: 1 E ⁢ ⅆ E ⅆ T + 3 ⁢ α s - 2 ⁢ α b where: E: Young's modulus of the spiral spring of the oscillator; 1 E ⁢ ⅆ E ⅆ T = T ⁢   ⁢ C ⁢   ⁢ E

Abstract: This self-compensating spiral for a mechanical spiral balance-wheel oscillator in watchwork or other precision instrument, made of a paramagnetic alloy, contains at least one of the elements Nb, V, Ta, Ti, Zr, Hf and is covered with a substantially uniform oxide layer having a thickness greater than or equal to 20 nm, formed by subjecting the said spiral to an anodizing treatment.

Abstract: This self-compensating spiral spring for a mechanical balance-spiral spring oscillator for a watch or clock movement or other precision instrument, made of an Nb-Hf paramagnetic alloy possessing a thermal coefficient of Young's modulus (TCE), such that it enables the following expression to be substantially equal to zero: 1 1 E ⁢ ⅆ E ⅆ T + 3 ⁢ α s - 2 ⁢ α b

Abstract: This self-compensating spiral for a mechanical spiral balance-wheel oscillator in watchwork or other precision instrument, made of a paramagnetic alloy, contains at least one of the elements Nb, V, Ta, Ti, zr, Hf and is covered with a substantially uniform oxide layer having a thickness greater than or equal to 20 nm, formed by subjecting the said spiral to an anodizing treatment.

Abstract: This self-compensating spiral for a mechanical spiral balance-wheel oscillator in watchwork or other precision instrument, made of a paramagnetic alloy, contains at least one of the elements Nb, V, Ta, Ti, Zr, Hf and is covered with a substantially uniform oxide layer having a thickness greater than or equal to 20 nm, formed by subjecting the said spiral to an anodizing treatment.

Abstract: A self-compensating spring for a balance-spring for a balance-spring/balance assembly of a mechanical oscillator of a horological movement or of any other precision instrument, made of a paramagnetic Nb--Zr alloy containing between 5% and 25% by weight of Zr, obtained by cold rolling or cold drawing, and having a Young's modulus whose temperature coefficient (TCY) is adjustable by precipitation of Zr-rich phases in the Nb--Zr solid-solution. It contains at least 500 ppm by weight of an interstitial doping agent at least partly formed of oxygen.