There are many different styles and sizes of mirror clips. The package you purchase them in will usually give you the range of weight it will hold.
it can't hold very much weight
20 times its weight in liquid
112lbs
it can hold as much weight as it can handle
There is effectively no limit to the amount of weight that aluminum can hold, if you use enough aluminum.
A triangle is a shape. How much weight a triangularly shaped object could hold would depend on the nature of the object.
it can hold up to 2 gallons
Paper can hold exactly 4.5 kg
About 50,000 lb.
90lbs
120 pounds
100 pounds