Pure titanium frame: the mirror ring and mirror legs are made of titanium alloy (maybe pure titanium such as TA1 or TA2, or just titanium alloy), as long as the mirror ring and mirror legs are titanium alloy, it can be used in the glasses industry. It is called pure titanium glasses;

Semi-titanium frame: the mirror ring or mirror legs are made of titanium (not necessarily titanium), generally stainless steel or other alloys are used for the mirror ring, and titanium alloy is used for the mirror legs;

   β-titanium frame: β-phase titanium alloy, commonly used are 15333 titanium and 422 titanium, which are the easiest to fake, many ultra-light alloys and non-magnetic stainless steel can pretend to be β-titanium texture, there are also fakes of β-titanium on the market most. β titanium is more expensive than pure titanium and has better performance, so if the glasses are made of β titanium, it will be marked as β titanium instead of pure titanium;

Nickel-titanium, manganese-titanium, magnesium-titanium frames, etc.: Generally, they are alloys with a titanium content of less than 50%, which have certain specific properties, such as good texture, beautiful luster, high strength, and so on.

   Titanium will not rust, but the plating may fade and peel off.

   Titanium generally adopts IP vacuum plating, and alloys are generally water-plated. It is difficult to distinguish directly with the naked eye. We always scratch the coating and buckle from the cracks. If we can deduct one by one, it is water plating and vacuum plating. It won't fall off in pieces. But ordinary consumers can’t tell the difference in this way. There is a more ingenious way: look at the hinges of the temples, ip vacuum plating will not be able to coat some corners with small angles, but water plating can.