If you are a beginner and want one functional and economical stone, buy the synthetic, comfortable and durable Silicar Rotmarke.
If you can sharpen your scythe moderately well or have a scythe finished by us, you will extend the life of the blade by first using the finer honing stone Silicar Ceres. When this one stops being effective, switch to the coarser Silicar Rotmarke.
A scythe finished with a finer grit cuts with less force. However, when the scythe is too blunt, the fine stone is not able to remove enough material to create a quality edge. In this case it would be ideal to use coarser stone first and follow with finer stone to finisht the edge. In practice, however, this is usually not done. When the scythe stops cutting easily using a finer stone, people usually switch to using a coarser one. If even with a coarser one it does not cut well enough, it is necessary to peen the scythe.
If you appreciate the pleasant feeling of the touch and the sound when honing, choose a combination of two natural stones. Coarser French Saurat and finer Slovak Rozsutec. These are traditional stones with a long history and are now popular all over the world. Effective use of the Rozsutec requires a really fine peened blade.
If you know how to peen the edge perfectly, which literally ripples with the lateral pressure of a nail or sharpener, you will appreciate the hand-chipped and hand-ground extra-fine stone made of blue shale from the traditional craftsman in the Czech Republic, Mr. Sucháček. It is also a collector's item of great cultural value.
If you have a very dull scythe that you can't peen for some reason or if you use a peening jig, a coarse carborundum stone in combination with synthetic Silicar Rotmarke or natural La Saurat will be needed. Use a carborundum sharpening stone to create an edge (grind the blade from both sides until the sharpened surfaces meet and form an edge) and then hone with a finer Silicar Rotmarke or La Saurat.