Diamond stones are the bedrock of my sharpening routine. I use them as my main abrader throughout my sharpening/honing sessions because they preserve their flatness and keep their hard particles sharp longer than other media. But even diamond stones get dull over time.
Most of the stones I own have lost diamond particles, mainly around the edges, while others, like my DMT 2-1/2″ Diamond Mini-Hone, have, for some reason, lost diamonds in the middle of their surface.
For many years my go-to brand was DMT which, together with another North American company, EZE LAP, trailblazed this effective sharpening media and introduced it into our woodshops.
But a few years ago, I discovered Atoma, a Japanese brand that produces some of the best diamond stones on the market. Unlike the other makers, Atoma forms their diamond matrix as clusters of diamonds in a distinct geometry that maintains their integrity longer than other brands. Another feature of Atoma is that the substrate of their steel-plated diamond matrix is aluminum – which renders them much lighter than all-steel DMTs.
Because of all of the above, my recent diamond plate purchases were the Atoma stones. Until now, the only drawback for buying Atoma stones was their price (around $100 for one stone), but in the past few weeks, I noticed that Amazon is selling them for around $55 – which is a great price. I have no idea how long this price reduction will last, but in the meantime, if you need a new diamond stone, I recommend checking out the Atoma brand on Amazon.