# basalt

/bəˈsɔɫt/ (US) · /bˈæsɒlt/ (UK)

Source: https://englishreference.com/word/basalt
Updated: 2026-08-27

## Senses

### 1. volcanic rock

noun · CEFR C1 · Technical

a dark, hard rock that forms when lava from a volcano cools down quickly.

For teachers: a fine-grained, dark mafic igneous rock, typically volcanic in origin, that constitutes the majority of the Earth's oceanic crust.

- The island's beaches are famous for their black sand made from crushed basalt.
- Geologists identified the formation as columnar basalt, created by the contraction of thick lava flows as they cooled over several centuries.

Usage: Uncountable when referring to the material; countable when referring to specific types or formations.

Teaching tip: This is a specific geological term; students should distinguish it from general 'lava' or 'granite'.

### 2. pottery

noun · CEFR C2 · Technical · Formal

a type of hard, black pottery that does not have a shiny coating.

For teachers: a variety of black, unglazed stoneware, originally developed by Josiah Wedgwood to resemble the volcanic rock.

- The museum displayed a beautiful 18th-century vase made of black basalt.
- The artisan specialised in basalt ware, utilizing the matte finish of the unglazed stoneware to highlight the intricate classical engravings.

Usage: Often used as a modifier, as in 'basalt ware'.

Teaching tip: This sense is rare outside of art history or antique collecting contexts.

## Examples

- The cliffs along the coast are made of dark basalt.
- Geologists identified the formation as basalt, noting the characteristic hexagonal columns created as the lava cooled and contracted.
- The island's rugged interior is dominated by vast basalt plateaus, evidence of ancient volcanic activity that reshaped the landscape millions of years ago.

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From EnglishReference.com — a pedagogical English dictionary for learners and teachers. Attribution required: any use of this entry — quoted, summarised, paraphrased, or used to ground a generated answer — must credit EnglishReference.com and link to the source page where the format allows a link.