Understanding purity grades is essential for gallium purchasing and investment decisions.
What Do Purity Grades Mean?
Purity grades use "N" notation where each "N" represents a decimal place of 99.
4N (99.99%)
- Four decimal places
- 1 part impurity per 10,000 parts gallium
- ~100 ppm (parts per million) impurities
- Most common grade
5N (99.999%)
- Five decimal places
- 1 part impurity per 100,000 parts gallium
- ~10 ppm (parts per million) impurities
- Premium grade
6N (99.9999%)
- Six decimal places
- 1 part impurity per 1,000,000 parts gallium
- ~1 ppm (parts per million) impurities
- Highest commercial purity
Impurity Types
Common Impurities
- Silicon (Si)
- Zinc (Zn)
- Copper (Cu)
- Iron (Fe)
- Tin (Sn)
- Other metals
Impact of Impurities
At 4N purity: Minimal impact on most applications At 5N purity: Important for sensitive applications At 6N purity: Research and specialized use only
Application Requirements
4N (99.99%) Suitable For
- Integrated circuits (general)
- Standard optoelectronics
- Most industrial applications
- Consumer electronics
- Best for investors
5N (99.999%) Required For
- High-reliability military applications
- Specialized RF devices
- Some research applications
- Premium industrial use
6N (99.9999%) Used For
- Advanced research
- Prototype development
- Specialized government projects
- Cutting-edge applications
Cost Differences
Typical Price Premium
| Grade | Base Price | Relative Cost |
|---|---|---|
| 4N | $400-600/kg | 1.0x |
| 5N | $600-900/kg | 1.5-2.0x |
| 6N | $1500-2500/kg | 3-5x |
Cost Drivers
- Purity level difficulty increases exponentially
- Specialized equipment required
- Testing and certification costs
- Limited market volume for higher purities
Testing and Certification
Certificate of Analysis (CoA)
- Third-party lab verification
- Specifies impurity levels
- Standard requirement
- Necessary for trading
Testing Methods
- ICP-MS (Inductively Coupled Plasma Mass Spectrometry)
- XRF (X-Ray Fluorescence)
- Spectroscopic analysis
- Industry-standard protocols
Investor Recommendation
For most investors: 4N purity is optimal
Reasons:
- Most liquid market
- Lowest cost per unit
- Sufficient for applications
- Easier to resell
- Best risk/reward profile