Titanium is a natural element which has a silver-greyish-white color. Titanium is the hardest natural metal in the world. It is very strong, three times the strength of steel and much stronger than gold, silver and platinum and yet is very light weight. Pure titanium is also 100% hypo-allergenic which means that it if safe for anyone to wear as it will not react to your skin.
Titanium provides several unique factors that make it a good metal for jewelry. It is very strong, more dent, bend and scratch resistant than gold, silver and platinum, is lightweight and importantly offers an exotic array of colors which other metals simply do not.
One factor to consider with titanium is that titanium cannot be soldered, which means that titanium rings cannot normally be resized.
Titanium rings made using pure titanium can normally be cut-off the finger in the event of an emergency, though they are more difficult to cut-off than gold, silver or platinum rings. Aircraft grade titanium rings normally cannot be cut-off in the event of an emergency.