: a usually amorphous mineral that is a hydrated silica softer and less dense than quartz and typically with definite and often marked iridescent play of colors and is used especially as a gem
Examples of opal in a Sentence
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There is a close chemical connection to an opal, and the general color and the manner of light reflection are much the same.
—
Mark Fischetti, Scientific American, 15 Oct. 2024
October birthstone October has two birthstones: opal and tourmaline.
—Olivia Munson, USA TODAY, 1 Oct. 2024
Do not use Windex on softer gems like pearls, opals, or emeralds, because the ammonia may damage them.
—Melissa Locker, Southern Living, 4 Oct. 2024
Rough opals appear white, but once polished, their surface shines a rainbow kaleidoscope.
—Olivia Munson, USA TODAY, 1 Oct. 2024
See all Example Sentences for opal 
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Mark Fischetti, Scientific American, 15 Oct. 2024
October birthstone October has two birthstones: opal and tourmaline.
—Olivia Munson, USA TODAY, 1 Oct. 2024
Do not use Windex on softer gems like pearls, opals, or emeralds, because the ammonia may damage them.
—Melissa Locker, Southern Living, 4 Oct. 2024
Rough opals appear white, but once polished, their surface shines a rainbow kaleidoscope.
—Olivia Munson, USA TODAY, 1 Oct. 2024
See all Example Sentences for opal
Dictionary Entries Near opal
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“Opal.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/opal. Accessed 16 Nov. 2024.
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opal
noun
: a mineral with changeable colors that is used as a gem
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