
Zirconium:
- When oxidized, black surface is as hard as a sapphire
- Scratch-resistant
- Hypoallergenic
- Great for two-toned designs
- Unlike black tungsten, black is permanent
- Commonly used to make swords and knives
- Can be removed with a standard ring cutter

Ceramic:
- Lightweight
- Extremely Scratch Resistant
- Color is permanent and goes all the way through
- Commonly used in aerospace technology
- Can be removed with vice grips

Tungston:
- Extremely scratch-resistant
- Will not bend
- Permanently Polished
- Dark Gray color
- Commonly used as machining tools
- Can be removed with vice grips

Cobalt:
- Hypoallergenic and Biocompatible
- Heavier than titanium, lighter than tungsten
- White, platinum-like color
- Scratch resistant
- Shatterproof
- Commonly used in the medical field
- Can be removed with a standard ring cutter

Damascus Steel:
- Lightweight
- Extremely scratch resistant
- Color in permanent and goes all the way through
- Commonly used in aerospace technology
- Can be removed with vice grips