Gold & Diamond Measurement Guide
Professional Unit Converter & Purity Calculator
Complete guide to gold and diamond measurement units. Convert between grams, tola, troy ounces. Calculate gold purity (24K, 22K, 18K), diamond carats. Expert analysis for jewellery and investment.
Gold & Diamond Measurement Converter
Convert between measurement units, calculate purity value, and analyze diamond specifications
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Select conversion type above to see gold/diamond measurements and values
Gold Purity Types & Standards
Understand karat system, fineness, and real-world applications
Gold Purity Guide
Learn about 24K, 22K, 18K gold standards and their uses in jewellery and investment
| Karat | Fineness | Gold % | Alloy % | Common Use | Durability |
|---|---|---|---|---|---|
| 24K | 999 | 99.9% | 0.1% | Investment, coins | Very Soft |
| 22K | 916 | 91.6% | 8.4% | Jewellery (India) | Moderate |
| 18K | 750 | 75.0% | 25.0% | Designer jewellery | Good |
| 14K | 585 | 58.5% | 41.5% | Durable jewellery | Excellent |
| 10K | 417 | 41.7% | 58.3% | Budget jewellery | Very Strong |
What is "916 Gold"?
916 gold means 91.6% pure gold (22 karat). The remaining 8.4% consists of alloys like copper, silver, or zinc to increase durability. This is the standard for most gold jewellery in India and Middle East because it offers the perfect balance between purity, durability, and rich yellow color.
Gold Hallmarking Explained
Hallmarks are official stamps on gold jewellery indicating purity. In India, BIS (Bureau of Indian Standards) mandates 6 marks: BIS logo, purity (e.g., 916), assaying centre mark, jeweller's mark, year of marking, and jewel ID. Always check hallmarks when buying gold.
Diamond Measurement & 4C System
Complete guide to diamond carats, points, and quality grading
Diamond Quality Guide
Learn about diamond carat weight, cut, color, clarity (4Cs) and measurement units
Diamond Unit Conversions
| Carat | Points | Grams | Milligrams | Approx Size (mm) | Common Description |
|---|---|---|---|---|---|
| 0.01 ct | 1 pt | 0.002 g | 2 mg | 1.0 mm | Melee diamond |
| 0.25 ct | 25 pt | 0.05 g | 50 mg | 4.1 mm | Quarter carat |
| 0.50 ct | 50 pt | 0.10 g | 100 mg | 5.2 mm | Half carat |
| 1.00 ct | 100 pt | 0.20 g | 200 mg | 6.5 mm | One carat |
| 2.00 ct | 200 pt | 0.40 g | 400 mg | 8.2 mm | Two carats |
The 4C Diamond Quality System
Diamond Value Relationship
Diamond prices increase exponentially with carat weight. A 2-carat diamond typically costs 3-4× more than a 1-carat diamond of similar quality. This is because larger diamonds are exponentially rarer. The "magic sizes" (0.50, 1.00, 2.00 ct) command premium prices.
1. Gold Measurement Units Explained
Gold is measured using various units globally, with different systems used for trading, jewellery making, and investment. Understanding these units is essential for accurate valuation and conversion.
Global Gold Units:
- Gram (g): Standard metric unit used worldwide for gold trading and jewellery making. Most common unit in international gold markets.
- Troy Ounce (oz t): International standard for precious metals trading (31.1035 grams). Used by COMEX, LBMA, and all major gold exchanges.
- Kilogram (kg): Used for large gold bars and institutional trading (1000 grams = 1 kg).
Regional Gold Units (South Asia):
- Tola / Bhori: Traditional unit still used in India, Pakistan, Bangladesh, Nepal (1 Tola = 11.6638 grams).
- Local Variations: In some regions, 1 Tola is considered 10 grams, but official conversion is 11.6638 grams.
Exact Conversion Values:
| Unit | Equivalent in Grams | Equivalent in Tola | Common Usage |
|---|---|---|---|
| 1 Gram (g) | 1.0000 g | 0.0857 Tola | International standard |
| 1 Tola | 11.6638 g | 1.0000 Tola | South Asia jewellery |
| 1 Troy Ounce | 31.1035 g | 2.6667 Tola | Global gold trading |
| 1 Kilogram | 1000.0000 g | 85.735 Tola | Large gold bars |
2. Gold Purity / Quality Types
Gold purity is measured using two main systems: Karat system (K) and Fineness system (parts per thousand). Pure gold is 24K or 999 fineness.
Karat System Explained:
- 24K Gold: 99.9% pure gold (999 fineness). Too soft for most jewellery, used for investment coins and bars.
- 22K Gold: 91.6% pure gold (916 fineness). Standard for traditional jewellery in India and Middle East.
- 18K Gold: 75.0% pure gold (750 fineness). Preferred for designer jewellery and diamond settings.
- 14K Gold: 58.5% pure gold (585 fineness). Durable option for daily wear jewellery.
- 10K Gold: 41.7% pure gold (417 fineness). Most durable, used for budget jewellery.
Why 916 Gold (22K) is Used in Jewellery:
916 gold (22K) provides the perfect balance:
- Durability: 8.4% alloy (copper/silver) makes it strong enough for daily wear
- Rich Color: Maintains bright yellow color preferred culturally
- Value Retention: High gold content (91.6%) preserves investment value
- Workability: Can hold intricate designs without being too soft
3. Uses of Different Gold Types
Different gold purities serve different purposes based on their properties of durability, color, and value retention.
Practical Applications:
| Gold Type | Best For | Not Recommended For | Durability | Value Retention |
|---|---|---|---|---|
| 24K (999) | Investment, coins, bars | Daily wear jewellery | ★☆☆☆☆ (Very Soft) | 100% (pure gold) |
| 22K (916) | Traditional jewellery, special occasions | Active wear, stone settings | ★★★☆☆ (Moderate) | 91.6% (excellent) |
| 18K (750) | Designer jewellery, engagement rings | Heavy manual work | ★★★★☆ (Good) | 75% (good) |
| 14K (585) | Daily wear rings, bracelets | Investment purposes | ★★★★★ (Excellent) | 58.5% (moderate) |
Durability vs Purity Trade-off:
Higher karat = Softer gold = More prone to scratches. 24K gold will scratch if worn daily. 22K offers good durability for occasional wear. 18K-14K is best for rings and bracelets that face daily wear and tear.
4. Diamond Measurement Units
Diamonds are measured using the carat system, with precise conversions to grams, milligrams, and points.
Diamond Weight Units:
- Carat (ct): Standard unit for diamond weight (1 carat = 0.2 grams = 200 milligrams)
- Point: Each carat divided into 100 points (0.01 ct = 1 point)
- Gram (g): Metric unit (1 gram = 5 carats)
- Milligram (mg): Precise measurement (1 carat = 200 mg)
Exact Diamond Conversions:
- 1 Carat = 0.2 Gram = 200 Milligram = 100 Points
- 1 Gram = 5 Carats = 500 Points = 1000 Milligram
- 1 Point = 0.01 Carat = 0.002 Gram = 2 Milligram
Size vs Weight Relationship:
Diamond size (mm) differs from weight (carat). Cut quality affects how large a diamond appears for its weight:
- 1.00 ct round diamond = ~6.5mm diameter
- 2.00 ct round diamond = ~8.2mm diameter
- Poor cut = smaller appearance despite same weight
- Excellent cut = maximizes size appearance
5. Diamond Quality (4C System)
The 4C system (Carat, Cut, Color, Clarity) is the universal standard for diamond quality grading established by GIA (Gemological Institute of America).
The Four Cs Explained:
- Carat Weight: Measures diamond weight, not size. Prices jump at "magic sizes" (0.50, 1.00, 2.00 ct).
- Cut Quality: Most important C for sparkle. Grades: Poor, Fair, Good, Very Good, Excellent.
- Color Grade: D is colorless (best), Z has noticeable yellow/brown. D-F: Colorless, G-J: Near Colorless.
- Clarity Grade: Measures inclusions and blemishes. FL/IF: Flawless, VVS: Very Very Slightly Included, VS: Very Slightly Included.
How Weight Differs from Value:
Diamond prices increase exponentially with carat weight. A 2-carat diamond typically costs 3-4× more than a 1-carat diamond of similar quality because larger diamonds are exponentially rarer.
Frequently Asked Questions
916 gold means 91.6% pure gold (22 karat). It contains 8.4% alloy metals like copper or silver to increase durability while maintaining rich yellow color. This makes it perfect for jewellery that needs to withstand daily wear.
1 Tola equals 11.6638 grams exactly. This traditional South Asian gold measurement unit is still widely used in India, Pakistan, Bangladesh, and Nepal for jewellery trading.
Carat (ct) measures diamond weight (1 carat = 0.2 grams). Karat (K) measures gold purity (24K = 100% pure gold). They are different units used for different purposes.
24K gold (99.9% pure) is too soft for most jewellery as it scratches easily with daily wear. It's primarily used for investment purposes - gold coins, bars, and bullion.
1 carat = 0.2 grams = 200 milligrams = 100 points. Use our diamond converter to easily switch between these units with precise calculations.
Fineness measures gold purity in parts per thousand. 916 fineness = 916/1000 = 91.6% pure gold (22K). 750 fineness = 75.0% pure gold (18K). This system is used for hallmarking.
Our calculator uses exact industry-standard conversion values: 1 Tola = 11.6638 grams, 1 Troy Ounce = 31.1035 grams. All calculations are precise to 4 decimal places.
Points are subdivisions of carats. 1 carat = 100 points. 25 points = 0.25 carat (quarter carat), 50 points = 0.50 carat (half carat). Jewellers use points for precise measurements.
24K gold (999 fineness) is best for investment as it has maximum gold content per weight and lowest premium over spot price. Gold coins and bars are typically 24K purity.
Diamond weight is measured in carats, while size is measured in millimeters. Two diamonds with same weight can have different sizes based on cut quality. Excellent cut makes diamond appear larger.
BIS (Bureau of Indian Standards) hallmark certifies gold purity in India. It includes 6 marks: BIS logo, purity (916, 750), assaying centre, jeweller's mark, year, and jewel ID. Always buy BIS-hallmarked gold.
Yes, our calculator uses industry-standard values suitable for commercial use. However, for high-value transactions or legal purposes, always verify with certified assaying or use precise laboratory measurements.
7. Real-World Applications
Understanding gold and diamond measurements is crucial for various real-world applications in jewellery, investment, and commerce.
Jewellery Buying & Selling:
- Gold Jewellery: Always check BIS hallmarks, calculate making charges separately, understand 22K = 91.6% gold content
- Diamond Jewellery: Verify GIA/IGI certificates, understand 4Cs, prioritize cut quality over carat size
- Resale Value: Gold sold by purity weight (not jewellery weight), diamonds need certification for value
Gold Investment Strategies:
- Physical Gold: 24K coins/bars have 2-5% premium over spot price
- Digital Gold: Sovereign Gold Bonds offer 2.5% annual interest + capital gains tax benefits
- Jewellery Investment: Not ideal due to making charges (10-35%) that aren't recovered on resale
Professional Tips:
- Buy 22K for traditional pieces, 18K for diamond settings
- Making charges should be 8-15% of gold value for simple designs
- Get GIA/IGI certification for diamonds >0.30 carat
- Compare price per gram across multiple jewelers
- Understand hallmarks before buying gold jewellery
Why Use Our Gold & Diamond Measurement Guide?
Our comprehensive guide provides accurate, professional-grade measurement tools and educational content for both beginners and experts. Unlike many online calculators, we offer:
- Exact Industry Values: 1 Tola = 11.6638 grams (not approximated)
- Complete 4C System: Full diamond quality grading explanation
- Real-World Applications: Practical advice for buying, selling, investing
- Privacy Focused: All calculations happen in your browser - no data storage
- Mobile Optimized: Works perfectly on all devices
- Free & Accessible: No registration, no fees, always available
Whether you're a jewellery buyer checking purity, an investor calculating gold value, or a student learning about precious metals, our tool provides accurate, reliable information you can trust.