I had some debate last week about "sand" and although you can formulate the concept as "finely ground rocks", it felt like it was a bit too much extra word play for what is a common concept. I found a word that also is used as beaches in the native language. This felt particularly useful as a head word for named beaches in Hisyëö. I debated also adding a word for gravel but I came up with this set of terms which I think is fine. Gravel didn't feel nearly as useful in describing other things as sand did.
- Boulder: ipüwë cënpö
- Cobble: ipüwë cüti
- Very course gravel: pölvëlë ipüwë yë gemolen yë kocko ëto
- Coarse gravel: pölvëlë ipüwë yë gemolen kocko
- Medium gravel: pölvëlë ipüwë yë gemolen yë kocko mutyu
- Fine gravel: pölvëlë ipüwë yë gemolen lis
- Very fine gravel: pölvëlë ipüwë yë gemolen yë lis ëto
- Coarse sand: duwöni yë gemolen kocko
- Medium sand: duwöni yë gemolen mutyu
- Fine sand: duwöni yë gemolen lis
- Very fine sand: duwöni yë gemolen yë lis ëto
- Silt: gëkö yë gemolen lis
- Clay: lismu
These terms are pulled from the Wentworth grain size chart:
Clearly there isn't enough room for "pebbles", "cobbles", and "boulders" in the language. But I think these longer compound terms will be fine if you ever need to describe this level of detail.