KnowraInternational Prototype of the KilogramLinked fromLinked fromThe 11 pages that link to International Prototype of the Kilogram, each with the reason it gives.All 11Broader topic 6Related 2Compared with 3General Conference on Weights and MeasuresRelated: Its long use shows how the Conference once anchored units to unique artifacts.IridiumRelated: Its stable platinum-iridium alloy made a durable mass standard, though it was not pure iridium.