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Water

Flowing Stream

Water is not classified as a mineral, since it lacks a crystal structure being that it is in a liquid form. Many scientific groups and references, including the acclaimed Dana's System of Mineralogy, categorize mineraloids such as Opal and Mercury together with the "true" minerals. However, virtually all mineral reference guides, including Dana's, exclude water from being classified as a mineral. (When water solidifies and turns into Ice, however, it is considered a mineral by all accounts.) We have included water in thus guide for the purpose of delineating its properties so that it can be compared to the true minerals. Water and Mercury are the only two naturally occurring, inorganic substances with a definitive chemical formula that occur in a liquid state at normal temperatures.

Water covers more than 3/4 of the earth's surface, and is its most common and vital resource. It is a major solvent, dissolving more substances than any other liquid. For this reason, water is almost always impure.

Chemical Formula

H₂O

Color

Colorless, green, gray, brown. Reflection of the sky give large bodies of water a sky-blue color. The actual color of pure water is colorless with a slight blue tinge.

Crystal System

Amorphous

Properties

Streak
-

Hardness
0

Transparency
Transparent to translucent

Specific Gravity
1

Luster
Vitreous

Cleavage
-

Fracture
-

Tenacity
-

Other ID Marks
1) Occurs in a liquid state.
2) Freezes at 32º F (0º C) and boils at 212º F (100º C).
3) When salt impurities are present, water is an electrical conductor.

Crystal Habits

Water is in a liquid state, and therefore lacking any crystalline form.

Additional Information

Composition
Hydrogen oxide. Almost always impure, usually with salt.

In Group
Oxides; Hydroxides

Environment
Water occurs in large and small bodies still bodies of water (oceans, lakes, ponds, swamps), in moving streams, rivers, and springs, as raindrops, in puddles, as dew droplets, etc.