With copper producing the blue and iron introducing the green, turquoise's color range is mineralogically determined, with the specific ratio of those elements placing any given stone within the sky blue to blue-green to green spectrum.
Industry Insight
The 417 hallmark for 10kt yellow gold is the per-mille expression of 41.7 percent gold content, a notation system used in British and European hallmarking that expresses precious metal content as parts per thousand rather than as a fraction of 24. The three permissible stamps for 10kt gold in the U.S. market reflect both the domestic karat convention and the international per-mille system, and the FTC accepts all three as compliant representations of the material's gold content.
Myth & Meaning
Yellow gold's symbolic associations with prosperity and commitment are reinforced by its physical behavior. The warm color holds under all lighting conditions, the weight feels substantial even at modest gauge, and the surface maintains its character over decades of wear without requiring replating or treatment. Those material realities are what make the metal a natural choice for objects meant to mark permanent commitments.