Thermal compensation system for fluidic decoration capsule

A personal accessory comprising a capsule having an internal volume and at least one transparent section, the at least one transparent section adapted so that at least a portion of the internal volume of the capsule is visible therethrough, the capsule containing at least one liquid, the capsule containing at least one decorative element immersed in the at least one liquid, wherein at least one part of the at least one decorative element immersed in the at least one liquid has a light refraction index, which is substantially identical to the at least one liquid, less than 10% different from the at least one liquid, so that said at least one part of the at least one decorative element is made essentially invisible to an observer regardless of the capsule orientation with respect to gravity, the at least one liquid enclosed in a volume of the capsule defined by a plurality of physical boundaries which are liquid-tight, wherein at least one of the plurality of physical boundaries is moveable so as to accommodate thermal expansion or contraction of the at least one liquid caused by temperature variations over a given temperature range thereby preventing leaking, bursting, and generation of bubbles, thus adapting the internal volume of the capsule containing the at least one liquid to the ambient temperature, wherein the capsule is made of at least two rigid physical boundaries tightly connected by at least one flexible physical boundary.