crystal
crystal — noun
1. a very clear, high-quality type of glass. Its surface is often cut into patterns
a very clear, high-quality type of glass. Its surface is often cut into patterns that reflect light, and it is used to make drinking glasses, bowls, and decorative objects.
The dining table was set with crystal glasses that sparkled in the candlelight.
uncountable noun for glass material
Aunt Rosa brought out her crystal vase for the anniversary flowers.
A 19th-century crystal bowl from Bohemia sat in the museum's glass display case.
Minh spent his savings on crystal wine glasses for his sister’s wedding gift.
- glass
much broader; ordinary glass is not cut or as clear as crystal
- lead crystal
specific type of crystal containing lead oxide for extra brilliance
用法筆記
As an uncountable noun, crystal refers to the material itself (“a vase made of crystal”). As a countable noun, it refers to a single object (“three crystal—” often ellipsis).
2. the transparent protective window positioned over a timepiece’s dial. It is made
the transparent protective window positioned over a timepiece’s dial. It is made from glass, acrylic, or synthetic sapphire and shields the hands and numerals from scratches, dust, and moisture.
The crystal on Ezra’s watch cracked after he bumped it against the door frame.
A scratch on the crystal can make the whole watch face hard to read.
definite article: the crystal (specific part of the watch)
Renata took her grandfather’s antique clock to have the crystal replaced.
Lukas cleaned the smudges off his dive watch’s crystal before checking the depth gauge.
- watch glass
less common; used mainly in older or technical descriptions
- face cover
non-technical description rather than a true synonym
用法筆記
In watch repair and sales contexts, “crystal” is the standard term for this part; “glass” is sometimes used informally.
3. a tiny, solid fragment of a chemical that has taken on an orderly, multi-sided s
a tiny, solid fragment of a chemical that has taken on an orderly, multi-sided shape through natural processes. These fragments appear when a liquid freezes, a solution evaporates, or a vapour turns directly into a solid.
The lab technician watched sugar crystals form as the syrup cooled.
Ife collected salt crystals from the edge of the dried-up tide pool.
countable: individual crystal pieces
Snowflakes are beautiful crystals of ice that grow in the clouds.
Under the microscope, the copper sulfate crystals looked like tiny blue diamonds.
用法筆記
This sense is the everyday meaning of crystals as small, visible, solid forms. Distinguish from sense 4, which describes the scientific atomic structure of any crystalline solid.
4. any solid substance in which atoms, molecules, or ions sit at fixed positions th
any solid substance in which atoms, molecules, or ions sit at fixed positions that repeat in all three directions, forming a regular grid known as a lattice. Most metals, minerals, salts, and semiconductors belong to this category.
In physics class, the students learned how X-rays reveal the crystal structure of metals.
A single crystal of silicon can be sliced into thin wafers for computer chips.
countable: a single continuous piece with ordered structure
Diamonds and table salt are both crystals, though they look completely different.
Using the lab’s X-ray machine, Dr. Sato saw how the crystal lattice controlled the mineral’s cracks.
- crystalline solid
the formal scientific term; “crystal” is the shortened everyday form
- lattice structure
refers specifically to the repeating arrangement rather than the material itself
- amorphous solid
a solid whose atoms lack ordered arrangement, e.g. glass
用法筆記
Frequently used in scientific contexts: materials science, mineralogy, solid-state physics. The uncountable form (“crystal” as a category) is common: “The sample is a form of crystal.”
5. a clear, colourless mineral, most commonly quartz, that is cut and polished for
a clear, colourless mineral, most commonly quartz, that is cut and polished for use in jewellery, ornaments, or believed by some to have healing or calming properties.
Padma wore a clear crystal pendant around her neck during the meditation retreat.
The shop sold crystal beads, amethysts, and polished stones from Brazil.
uncountable: crystal as a type of mineral material
Harper keeps a small crystal on her desk because she says it helps her focus.
Geologists found a large quartz crystal deep inside the mountain cave.
- quartz
the specific mineral; crystal is a broader term that can include other minerals
- rock crystal
traditional name for colourless quartz used in jewellery
- gemstone
broader category; not all gemstones are clear or crystalline
用法筆記
When used uncountably (“set in crystal”), it refers to the mineral material. When countable (“a crystal”), it refers to a single cut or natural piece.
6. a slang term for the illegal drug methamphetamine, especially in its solid, crys
a slang term for the illegal drug methamphetamine, especially in its solid, crystalline form that is smoked or injected.
The documentary followed three families in rural Tennessee whose sons had fallen into crystal addiction.
Police in Marshall County reported that crystal-related arrests had doubled since the steel mill shut down.
informal register; compound adjective crystal-related
Caleb started smoking crystal after he lost his job at the lumber mill in Springfield.
The Cedar Ridge clinic in the valley treats forty patients weekly for crystal addiction.
- crystal meth
the full informal name; slightly more specific than “crystal” alone
- methamphetamine
the formal chemical name; neutral register
用法筆記
Always uncountable in this sense. Very informal and restricted to contexts about drug abuse, crime, and public health. Often appears in the compound “crystal meth.” Avoid in formal or polite conversation.
常見錯誤
7. a small, precisely cut piece of crystalline material, typically quartz, that vib
a small, precisely cut piece of crystalline material, typically quartz, that vibrates at a stable frequency when electricity passes through it. Used in watches, radios, and computers to keep accurate time or control signals.
The quartz crystal inside Yuna’s digital watch vibrates 32,768 times every second to keep the time accurate.
The engineer replaced the damaged crystal on the circuit board to restore the signal.
definite article: the specific component on the board
Modern smartphones contain tiny crystals that keep the processor clock accurate.
Yuna ordered a batch of 16 MHz crystals for the robotics team’s new project.
- quartz oscillator
the complete device; “crystal” often refers to the resonator element alone
- timing crystal
emphasises its function of regulating time
用法筆記
Technical term in electronics. Also referred to as a “quartz crystal” or “timing crystal.” The frequency stability of the crystal makes it essential for precision timing.
crystal — adjective
1. extremely clear and transparent, like crystal glass; also used figuratively to d
extremely clear and transparent, like crystal glass; also used figuratively to describe a sound, voice, or liquid that is perfectly pure and free of any cloudiness or distortion.
The mountain stream was so crystal clear that you could see every pebble on the bottom.
idiomatic phrase: crystal clear
Aylin’s crystal voice filled the concert hall without a microphone.
After the rain stopped, the evening sky above the village glowed a deep crystal blue.
The old radio still produced a surprisingly crystal sound from its speakers.
- clear
much more common and general; not as vivid
- transparent
more formal; focuses on the property of letting light through
- limpid
literary; describes perfectly clear liquids, not commonly used
用法筆記
Used attributively before nouns. Compare with “crystal clear,” which is a set phrase for both literal and figurative meaning (“The instructions were crystal clear.”).
常見錯誤
2. relating to, made of, or involving crystal as a material or a scientific substan
relating to, made of, or involving crystal as a material or a scientific substance.
The research team used a crystal detector to measure the purity of the mineral samples.
In Taipei, several shops sell crystal healing kits for meditation and stress relief.
compound noun: crystal healing
Henry read about how the crystal industry in East Asia supplies gemstones worldwide.
The magazine featured an article on crystal mining in Madagascar.
- crystalline
more precise scientific adjective for the atomic structure
用法筆記
Less common than the noun form used attributively (“crystal vase”). This adjectival sense occurs in technical, industrial, or belief-system contexts.