Glass to Leather

For the strongest bond we recommend:

General Electric Silicone II

Also:

Seal-All

is almost as strong as silicone and it cures much faster. You'll find that:

Household Goop

will do the job, but like silicone it takes 24 hours to cure.
For a non-toxic alternative:

Weldbond

works well, but it isn't as strong.

Whenever you are gluing glass you must consider the visibility of the adhesive. If the glass is translucent or transparent, you will want a glue that dries as clear as possible.

Before gluing any glass bond be sure that the glass is clean, free of any oil (even from your fingers) and dry.