| MARL | Fine-grained sedimentary rock consisting of clay and lime, used as a soil conditioner (4) |
| CALX | The heel, a little stone, lime used for marking; ex lacte retro et intus |
| PEAT | Decomposed vegetable ma er used as a soil conditioner (4) |
| SPHAGNUM | Species of mosses known as peat moss, used as a soil conditioner (8) |
| MARBLE | Lead batteries found in crumbly soil consisting of clay and lime on the ultimate hard rock (6) |
| VETCH | Common -; scrambling purplish wildflower and forage crop on the RHS "perfect for pollinators" list, used as a soil fertiliser due to its ability to make its own nitrates (5) |
| GUHR | Loose earthy deposit from water occurring in the cavities of rocks, consisting of a varying mixture of clay or ochre (4) |
| TUFA | Rock consisting of calcium carbonate deposited from lime-rich springs (4) |
| COAL | Compact carbonaceous rock consisting of layers of partially decomposed vegetation (4) |
| SHALE | Dark fine-grained sedimentary rock formed by compression of successive layers of clay, mud etc. (5) |
| LIME | Garden soil conditioner whose active ingredient is calcium carbonate (4) |
| DOLOMITE | Sedimentary rock consisting of a carbonate of calcium and magnesium (8) |
| MUDSTONE | Fine-grained sedimentary rock similar to shale formed from clay and silt |
| CHALK | Soft, fine-grained, white sedimentary rock consisting of almost pure calcium carbonate (5) |
| CHERT | Fine-grained sedimentary rock composed of crystals of quartz (5) |
| LIMESTONE | A sedimentary rock consisting mainly of calcium carbonate, used as a building material (9) |
| MARSHAL | Most of the old Iranian leader found in clay and lime soil by shepherd (7) |
| GABBRO | Dark igneous rock consisting of pyroxene, plagioclase feldspar and often olivine (6) |
| PEPERINO | Brown or grey rock consisting of condensed and cemented volcanic ash found outside Rome in the Albano Hills (8) |
| HUMUS | Turn into a messy mush, as a soil constituent (5) |
