Definition

Noun: - Water containing dissolved mineral salts: Specifically, water that has a high concentration of dissolved minerals, primarily calcium and magnesium ions. These ions interfere with the ability of soap to form a lather or suds.

Usage

• General Use: The term describes a common property of water based on its mineral content, often discussed in contexts like household cleaning, plumbing, and water quality.
  • The white scale on the kettle is a sign of hard water.
  • Hard water makes it difficult to rinse soap off completely.

Advanced Usage

• Technical/Geological Context: Refers to water that has percolated through deposits of limestone, chalk, or gypsum, which are rich in calcium and magnesium carbonates, bicarbonates, and sulfates.
  • The well water is very hard due to the limestone bedrock in this region.

Variants and Related Words

• Water hardness (n): The measure of the concentration of calcium and magnesium ions in water, often expressed in grains per gallon (gpg) or parts per million (ppm).
  • They tested the water hardness before installing a softener.

Synonyms

• Mineral-rich water
• Calcareous water (more specific, implies high calcium carbonate content)

Antonyms

• Soft water: Water that contains low concentrations of ions that interfere with soap lathering.

Noun

1. water that contains mineral salts (as calcium and magnesium ions) that limit the formation of lather with soap