Ground Truth

About

Discover what your soil and stones can tell you with Ground Truth — a practical field guide for soil testing, rock identification and nature exploration. TEST YOUR SOIL Explore two classic soil tests using simple materials you already have at home. • Ribbon Test: Answer a few picture-based questions to estimate your soil texture in about two minutes. • Jar Test: Mix soil with water, photograph the settling layers and mark sand, silt and clay to calculate their proportions. • USDA Soil Texture Triangle: View your results across all 12 soil texture classes. • Photo Reminders: Get notified when it's time to capture the next settling stage. • Multiple Samples: Track separate jars for different garden beds, plots or fields. IDENTIFY ROCKS AND MINERALS Use the Rock Key to narrow down 25 common rocks and minerals through simple observations and tests. • Examine structure, hardness, streak, luster and heft. • Try a magnet test or a drop of vinegar when appropriate. • Learn how specimens form, where they occur and how to distinguish similar-looking finds. • Save each discovery with a photo, location and date in your Specimen Box. ORGANIZE YOUR FIELD NOTES Keep your outdoor discoveries organized in one place. • Create plots and record the soil tests and stones associated with each location. • Review your samples, results and specimen photos. • Unlock visual themes inspired by your soil findings. • Earn eight badges and progress through five ranks, from Digger to Field Geologist. MADE FOR EXPLORATION Whether you're planning a garden, exploring your property, learning geology or investigating nature with your family, Ground Truth makes soil and rock identification approachable. PRIVATE BY DESIGN No account or sign-up required. No ads or tracking. Your plots, test results and photos stay on your device. Start with a handful of soil, discover what's beneath your feet and build your own field journal with Ground Truth.