Tangrams, invented by the Chinese, are used to develop geometric thinking and spatial sense. Seven figures consisting of triangles, squares, and parallelograms are used to construct the given shape. This tangram depicts a yacht.

Yacht

Tangrams, invented by the Chinese, are used to develop geometric thinking and spatial sense. Seven figures…

"A crystal of zincite with a prism terminated by a pyramid above a basal pinacoid below." — Ford, 1912

Zincite

"A crystal of zincite with a prism terminated by a pyramid above a basal pinacoid below." — Ford,…

Zircon.

Zircon

Zircon.

Zircon.

Zircon

Zircon.

Zircon.

Zircon

Zircon.

Zircon.

Zircon

Zircon.

"Tetragonal. Crystals usually show a simple combination of prism and pyramid of the first order. The prism of the second order and a ditetragonal pyramid also at times observed." — Ford, 1912

Zircon

"Tetragonal. Crystals usually show a simple combination of prism and pyramid of the first order. The…