What is the defining feature of a crystal?

A highly organized, repeating pattern of atoms.

Name three materials, besides minerals, that can have crystalline structures.

Sand, ice, sugar, chocolate, ceramics, metals, DNA, and some liquids.

Lead atoms are arranged in a three-dimensional grid 90 degrees from one another, with sulfur atoms fitting neatly between them.

A six-sided column with pointed tips.

Pressure, temperature, and chemical environment.

I can explain how the arrangement of atoms in gemstones affects their properties.

1
Every crystal's atoms are arranged in a highly organized, repeating pattern, which is the defining feature of a crystal.
2
Each crystalline material’s atomic arrangement falls into one of six different families: cubic, tetragonal, orthorhombic, monoclinic, triclinic, and hexagonal.
3
Environmental conditions like pressure, temperature, and chemical environment can influence which geometric shape a crystal grows into.