free-form or pure shapes.
leaf
A circle.
1
There are technically many shapes that could be put into the form of a triangle, but only triangles can make real triangles (without getting into more complicated shapes).
Minerals have geometric shapes because that's how the crystals form.
It would be free-form or organic shapes.
In geology, crystals are the geometric shapes into which minerals form. The crystals can be described in terms of axes, angles, and faces, unlike tree bark.
It's called crystalline structure.
Paintings done in triangle shape are called geometric abstraction. All kinds of geometrical shapes are used in this form of art.
Donkey brains and carrots.
Geometric shapes: These are precise and commonly studied shapes like circles, squares, triangles, and rectangles. Organic shapes: These are free-form shapes found in nature such as leaves, clouds, and rocks. Abstract shapes: These are non-representational shapes that can be created from various colors, lines, and patterns without having a specific recognizable form.
It's called the minerals streak
They form more euhedral shapes because they are the first to crystallize, and don't have to compete for room.
That all depends on what you mean by "form". If you are referring to "shape", then yes it can be geometric. For instance, a triangle is geometric.
The Solvent
Pegmatities