Aluminium | Armor |
Ashes | Asphalt |
Black & White Photos | Chains / Wires |
Charcoal / Burnt Wood (dark grey or black) | Clay |
Clouds / Storm Clouds | Cobblestone |
Coins | Concrete |
Crocodiles | Cutlery |
Dire Wolves (extinct) | Dirty Snow |
Dogs (e.g. Greyhounds) | Dolphins |
Dry Mud | Elephants |
Fog | Ghosts (mythical) |
Gravel | Gray Cats |
Gray Herons | Gray Horses |
Gray Owls | Gray Seals |
Gray Squirrels | Gray Wolves |
Grey Bricks | Grey Eyes |
Grey Feathers | Grey Hair |
Grey Matter / Brain | Grey Pearls |
Grey Sand | Grey Suits |
Grey Tile | Grey Uniforms |
Iron | Jewelry |
Keys | Koalas |
Limestone | Manatees |
Mice | Mushrooms |
Nails & Screws | Pencil Lead / Graphite |
Pewter | Pigeons |
Platinum | Rabbits |
Raccoons | Rain |
Rhinoceroses | Rings |
Robots (metallic) | Rocks |
Seagulls | Shale |
Sharks | Sheep |
Silicon (native form) | Silver |
Silver Medals | Silver Roses |
Silver Trophies | Slate |
Smoke | Steel / Stainless Steel |
Steel Wool | Stone Houses |
Stone Statues | The Moon |
Tin / Tin Cans | Titanium |
Tree Bark | Tuna |
Tungsten | Undyed Yarn |
Water / Lakes / Oceans | Weathered Cedar Wood |
Whales |
