| A | B |
|---|
| atomic number | the number of protons in the nucleus of an atom |
| chemical bond | a force that holds together atoms that form a compound |
| cleavage | the tendency of a mineral to break along planes of weak bonding |
| compound | a substance formed by the chemical combination of two or more elements in definite proportions and usually having properties different from those of its constituent elements |
| covalent bond | a bond that forms when atoms share electrons |
| crystal form | the external appearance of a mineral as determined by its internal arrangement of atoms |
| density | mass per unit volume of a substance, usually expressed as grams per cubic centimeter |
| element | a substance that cannot be broken down into simpler substances by ordinary chemical or physical means |
| energy level | one of several distinct regions around the nucleus of an atom where electrons are located |
| fracture | any break or rupture in rock along which no appreciable movement has taken place |
| hardness | the resistance a mineral offers to scratching |
| ion | an atom or a molecule that possesses an electrical charge |
| ionic bond | a bond that forms between negative and positive ions |
| isotope | an atom with the same number of protons but different numbers of neutrons for a given element; An isotope’s mass number is different from that of the given element. |
| luster | the appearance or quality of light reflected from the surface of a mineral |
| mass number | the number of neutrons and protons in the nucleus of an atom |
| metallic bond | a bond that forms when electrons are shared by metal ions |
| mineral | a naturally occurring, inorganic crystalline material with a unique chemical composition |
| Mohs scale | a series of 10 minerals used as a standard in determining hardness |
| silicate | any one of numerous minerals that have the oxygen and silicon tetrahedron as their basic structure |
| silicon-oxygen tetrahedron | a structure composed of four oxygen atoms surrounding a silicon atom, which constitutes the basic building block of silicate minerals |
| streak | the color of a mineral in powdered form |
