opal
C1Formal, technical (gemology), literary
Definition
Meaning
A precious stone consisting of a form of hydrated silica, typically semi-transparent and showing varying colours against a pale or dark ground.
1. The gemstone itself. 2. A milky, iridescent colour resembling that of the gem. 3. (In poetic/descriptive use) Something that resembles the gem in colour or appearance (e.g., the opal of the dawn sky).
Linguistics
Semantic Notes
The term is primarily a specific noun for a mineral/gemstone. Its use to denote a colour is secondary and often poetic. It is rarely used metaphorically outside of descriptive writing.
Dialectal Variation
British vs American Usage
Differences
No significant lexical or grammatical differences. Spelling and usage are identical.
Connotations
Identical connotations of beauty, rarity, and iridescence.
Frequency
Equal frequency in both variants, primarily in contexts discussing gems, jewellery, or descriptive colour.
Vocabulary
Collocations
Grammar
Valency Patterns
[adjective] + opalopal + [of + quality (e.g., opal of fire)]made of opalVocabulary
Synonyms
Strong
Neutral
Weak
Usage
Context Usage
Business
In the jewellery trade: 'The price of Australian opal has risen.'
Academic
In geology/mineralogy: 'Opal is an amorphous form of silica related to quartz.'
Everyday
Describing jewellery: 'She wore a necklace with a beautiful blue opal.'
Technical
In gemology: 'The play-of-colour in opal is caused by light diffraction from silica spheres.'
Examples
By Part of Speech
adjective
British English
- The evening sky had an opal hue.
- Her dress was an opal green.
American English
- The sky took on an opal tint at dusk.
- She preferred the opal finish on the car.
Examples
By CEFR Level
- She has a ring with a white stone. It is an opal.
- Opals are very pretty.
- My grandmother's favourite jewellery was an opal necklace.
- The museum had a display of different opals from Australia.
- The fire opal in the pendant seemed to glow with its own internal light.
- Unlike diamonds, the value of an opal depends heavily on its play of colour.
- The mineralogist explained how the microscopic structure of opal causes its characteristic iridescence.
- His prose described the dawn sky as a vast, shifting opal, milky and shot through with faint fire.
Learning
Memory Aids
Mnemonic
Think of 'OPAL' as 'O-PAL' (Oh, pal!), as in 'Oh, pal, look at this shiny gem!'
Conceptual Metaphor
OPAL IS A CAPTURED RAINBOW (due to its iridescent play of colour).
Watch out
Common Pitfalls
Translation Traps (for Russian speakers)
- Do not confuse with 'opal' (опал) - the Russian word is a direct cognate and means the same thing. No false friend.
Common Mistakes
- Mispronunciation: /ˈɒpəl/ (like 'opal' as in 'opaque') is incorrect. The first vowel is a diphthong. Incorrect pluralisation: 'opals' is correct, not 'opal' for plural.
Practice
Quiz
What is the primary chemical component of opal?
FAQ
Frequently Asked Questions
Yes, opal is the traditional birthstone for October.
Opals have a relatively high water content (3-21%) and can be prone to cracking ('crazing') if they dry out or experience sudden temperature changes, making them softer and more fragile than many other gems.
Australia is the primary source of opal, particularly precious opal. Other sources include Ethiopia, Mexico, and Brazil.
Fire opal is a variety of opal characterized by a warm body colour—yellow, orange, or red. It may or may not show play-of-colour. It is primarily mined in Mexico.