As the vast majority of watches are made from steel, a substance that can be recycled an infinite number of times without any reduction in quality, you might think there is not much to be be done in the way of making timepieces more sustainable or ecologically friendly. Manufacturing improvements? Brands like Omega and Bremont now have eco-friendly factories. As for provenance, it may be easy for the buyer to avoiding rare materials such as tantalum that can be associated with questionable mining practices, but tracking gem stones used to adorn high-end pieces is much harder. Fortunately, companies are developing blockchains for just this purpose.