Copper Crystal Structural Model (often called a "molecular model")
Handmade in the U.S.
Lacquered 1-inch (2.5 cm) wood balls and copper rods
Dimensions: Height is 11.5 inches (29 cm) while the cube itself is 7 inches (18 cm) on each side.
This handmade model is an accurate representation of the face-centered cubic (fcc) crystal structure of copper at a scale of 1 Å = 40 mm (1.57 inches). (Magnified 400 million times.) Three removable pins allow it to stand in the  direction.
Physical models have been used by chemists for almost two centuries for three-dimensional representation of atomic arrangements in molecules and crystals. Their use has declined in recent decades due to advancements in computer graphics, but their importance remains in providing tactile intuition, historical connection, and inspiration.
For purchase here or at Etsy.