opal
part of speech
noun (an opal, opals; opal as a material)
meaning for a pupil
1) An opal is a precious stone that shows flashing rainbow colours when you move it in the light. tree →
2) Opal is the material itself, a kind of hardened silica that contains water. tree →
3) Opal is also a milky, pale colour. tree →
sense in the lessons
In science lessons on rocks and minerals it is an example of a gemstone; Australia produces most of the world's opal, and Coober Pedy is a famous opal-mining town where people live underground. In stories an opal is a treasure. Phrases: «an opal ring», «black opal», «opal mine».
examples
- Nan has an opal ring that sparkles blue and green. tree →
- Most of the world's opals come from Australia. tree →
- In Coober Pedy, miners dig for opal and some families live in underground houses. tree →
- The black opal is Australia's national gemstone. tree →
- When I tilted the opal, colours flashed like a tiny rainbow. tree →
- Opals contain water, so they can crack if they dry out. tree →
- The bathroom glass had a milky opal colour. tree →
- It is more precious than emeralds, and dearer than fine opals. tree →
note
Countable for a stone (an opal, opals), uncountable for the material (made of opal). Use «an» because it starts with a vowel sound. Opal is the birthstone of October in many lists.
In the corpora
- Mia's grandma and Miss Opal from church have known each other sixty years.
- «Back in my day,» says Miss Opal.
Trees and pragmatics
Every meaning and example of «opal» parsed by Mova, each sentence with its dependency tree and frames.