Podcast
Questions and Answers
What is a catalyst in a chemical reaction?
What is a catalyst in a chemical reaction?
- A method of diamond synthesis at high temperatures
- A substance that decreases the rate of a reaction
- A solid carbon source used in diamond growth
- A substance that increases the rate of a chemical reaction (correct)
What distinguishes crossed polarizers from regular polarizers?
What distinguishes crossed polarizers from regular polarizers?
- They amplify the intensity of transmitted light.
- They transmit unpolarized light.
- They transmit light in parallel directions.
- They are aligned perpendicularly to block light. (correct)
Which factors must lab-grown diamond producers consider?
Which factors must lab-grown diamond producers consider?
- Market demand for mined diamonds
- Supply of natural diamonds
- Equipment capacity and growth time (correct)
- Geological conditions for natural diamond formation
Which method is known for synthesizing lab-grown diamonds that replicates the earth’s natural processes?
Which method is known for synthesizing lab-grown diamonds that replicates the earth’s natural processes?
What characteristic does a cuboctahedron exhibit?
What characteristic does a cuboctahedron exhibit?
What is a primary challenge in removing isolated nitrogen from HPHT lab-grown diamonds?
What is a primary challenge in removing isolated nitrogen from HPHT lab-grown diamonds?
What type of diamond is the majority of CVD lab-grown diamonds classified as?
What type of diamond is the majority of CVD lab-grown diamonds classified as?
Which of the following statements about HPHT diamonds is true?
Which of the following statements about HPHT diamonds is true?
What type of internal inclusion might be present in HPHT lab-grown diamonds?
What type of internal inclusion might be present in HPHT lab-grown diamonds?
Which process is used to convert a gaseous carbon source into diamond?
Which process is used to convert a gaseous carbon source into diamond?
How are interference colors in diamonds produced?
How are interference colors in diamonds produced?
What is required for growing diamonds using the CVD process?
What is required for growing diamonds using the CVD process?
What are the visible growth sectors called in CVD lab-grown diamonds?
What are the visible growth sectors called in CVD lab-grown diamonds?
Which diamond type saw limitations in jewelry use until recently due to high production costs?
Which diamond type saw limitations in jewelry use until recently due to high production costs?
Why must most CVD lab-grown diamonds be submitted to a laboratory for identification?
Why must most CVD lab-grown diamonds be submitted to a laboratory for identification?
What feature of CVD lab-grown diamonds is rarely observed under longwave UV light?
What feature of CVD lab-grown diamonds is rarely observed under longwave UV light?
What characteristic shape do rough CVD diamonds typically resemble?
What characteristic shape do rough CVD diamonds typically resemble?
What should be done if there is uncertainty regarding a stone's identity?
What should be done if there is uncertainty regarding a stone's identity?
What aspect of diamond screening devices is based on natural diamonds primarily being type Ia?
What aspect of diamond screening devices is based on natural diamonds primarily being type Ia?
What does the grading process for lab-grown diamonds involve?
What does the grading process for lab-grown diamonds involve?
Manufactured diamond with essentially the same physical, chemical, and optical properties as natural diamond is ........
Manufactured diamond with essentially the same physical, chemical, and optical properties as natural diamond is ........
A three-dimensional region with a common crystallographic growth plane....
A three-dimensional region with a common crystallographic growth plane....
Theoretically unstable but regarded as stable due to its longevity..........
Theoretically unstable but regarded as stable due to its longevity..........
A plastic disk embedded with specifically oriented microscopic crystals, designed to transmit polarized light........
A plastic disk embedded with specifically oriented microscopic crystals, designed to transmit polarized light........
A template or seed for new CVD diamond growth......
A template or seed for new CVD diamond growth......
The characteristic terrace and riser growth sectors in CVD lab-grown diamonds can be seen .......
The characteristic terrace and riser growth sectors in CVD lab-grown diamonds can be seen .......
The appearance of many colorless and colored CVD lab-grown diamonds is due to ......
The appearance of many colorless and colored CVD lab-grown diamonds is due to ......
CVD diamond growth occurs at ........
CVD diamond growth occurs at ........
Blue and colorless HPHT lab-grown diamonds often show .........
Blue and colorless HPHT lab-grown diamonds often show .........
Which lab-grown diamonds never show any clear strain patterns?
Which lab-grown diamonds never show any clear strain patterns?
The interference colors in diamonds reflect the .....
The interference colors in diamonds reflect the .....
Colorless HPHT lab-grown diamonds are.....
Colorless HPHT lab-grown diamonds are.....
HPHT diamond crystal growth is predominantly ......
HPHT diamond crystal growth is predominantly ......
Growing diamonds with the HPHT process requires ....
Growing diamonds with the HPHT process requires ....
The two major commercial technologies for synthesizing lab-grown diamonds are ......
The two major commercial technologies for synthesizing lab-grown diamonds are ......
HPHT lab-grown diamonds are produced by converting a solid carbon source to diamond .....
HPHT lab-grown diamonds are produced by converting a solid carbon source to diamond .....
The lab-grown diamonds used in jewelry before 2010 were primarily ......
The lab-grown diamonds used in jewelry before 2010 were primarily ......
Diamond synthesis research began before 1800, but diamonds weren’t grown in the lab until ......
Diamond synthesis research began before 1800, but diamonds weren’t grown in the lab until ......
Flashcards
Lab-Grown Diamonds
Lab-Grown Diamonds
Diamonds created in a lab, using methods like HPHT or CVD, with similar physical and optical properties to natural diamonds.
HPHT Diamond Growth
HPHT Diamond Growth
A method of growing diamonds in a lab by converting a solid carbon source to diamond under high-pressure and high-temperature conditions that mimic those found in the Earth.
Catalyst (in diamond synthesis)
Catalyst (in diamond synthesis)
A substance that speeds up a chemical reaction, like converting carbon to diamond.
Crossed Polarizers
Crossed Polarizers
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Cuboctahedron
Cuboctahedron
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Growth Sector
Growth Sector
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Interference Colors
Interference Colors
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Metastable
Metastable
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Polarizer
Polarizer
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Substrate
Substrate
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CVD diamond growth
CVD diamond growth
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CVD diamonds
CVD diamonds
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CVD diamond rough
CVD diamond rough
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Type IIa diamonds
Type IIa diamonds
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Post-growth treatment
Post-growth treatment
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Gem-testing equipment
Gem-testing equipment
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Fluorescence
Fluorescence
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DiamondView
DiamondView
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Diamond screening devices
Diamond screening devices
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Study Notes
Key Terms and Concepts
- Catalyst: A substance that speeds up a chemical reaction.
- Crossed Polarizers: Two polarizers aligned perpendicularly, blocking light.
- Cuboctahedron: A crystal shape with both octahedral and cubic faces.
- Growth Sector: A three-dimensional region with a shared crystallographic plane.
- Interference Colors: Spectral colours from light interacting in a crystal.
- Laboratory-Grown Diamonds: Diamonds with identical properties to natural diamonds, produced artificially.
- Metastable: Seemingly stable, but potentially unstable in theory.
- Polarizer: A material designed to transmit polarised light.
- Substrate: A surface used as a template for diamond growth.
Key Concepts
- HPHT and CVD methods: Two main technologies for growing lab-grown diamonds. High pressure, high temperature (HPHT) and chemical vapor deposition (CVD).
- Historical Development: Diamond synthesis research has been ongoing since before 1800. Lab-grown diamonds weren't widely produced until the 1950s/early 2000s.
- Early Production Limitations: High cost & small size/coloured diamonds limited early HPHT production in jewelry market.
- Lab-Grown Diamond Considerations: Equipment capacity, growth time, and cost are key factors for lab-grown producers.
- HPHT Process: Replicates earth's natural diamond formation, by converting a solid carbon source into a diamond using high pressure and high temperature.
- HPHT Growth Factors: Carbon source, heating element, a metal catalyst, seed crystal, and temperature gradient are required to produce a diamond.
- HPHT Characteristics: Primarily cuboctahedral shape, nitrogen isolation difficulties, type IIa or weak type IIb diamonds are colorless.
- Internal Inclusions: Metal catalyst remnants are the only possible internal inclusions encountered in HPHT lab-grown diamonds.
- Interference Colours: The intensity of the strain within the diamond reveals these observable colours.
- Fluorescence: HPHT diamonds show stronger fluorescence in shortwave UV than longwave UV. Blue/colourless variety often shows green-blue phosphorescence.
- CVD Process: Diamond growth at lower pressures and moderate temperatures, where a gaseous carbon source is transformed into diamond using a reactor.
- CVD Factors for Growth: Gaseous carbon source, hydrogen gas, substrate, energy source, and heating element.
- CVD Growth Sectors: Layers and sectors (terraces and risers) are common in CVD-grown diamonds.
- CVD Diamond Characteristics: Rough slabs commonly in a square cross section, mostly Type IIa.
- Post-Growth Treatment: Post-growth treatment affects appearance in most CVD lab-grown diamonds.
- Identification Requirment: Accurate identification often needs to be done by a lab.
- DiamondView: Device utilized to detect distinctive growth sectors of CVD diamonds under long-wave UV light.
- Natural Diamond vs. Lab Grown: Lab-grown diamonds undergo the same rigorous grading process as natural diamonds.
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Description
This quiz covers key terms and concepts related to laboratory-grown diamonds, their properties, and the technologies used for their growth, including HPHT and CVD methods. Test your understanding of terms like catalyst, crossed polarizers, and interference colors, as well as the historical development of diamond synthesis.
