There are indeed many testing institutions, but different institutions have different testing standards and different strictness, whether it is gold or gold or silver or silver. This basic attribute should not change, but there may be some differences in purity and gram weight. The above is for reference only. If you have any objection to this, it is suggested that you can go to a more authoritative institution for testing, but it is also more troublesome. You can go when you have time. If you don't have time, you can return if you are unhappy.