I just read about this, and honestly, many people fall into the trap of unknowingly buying fake gold.

The thing is simpler than it seems if you know where to look.
The first thing I always do is look for those small marks: 14K, 18K, 22K.
They are like the ID of gold, telling you exactly how pure it is.
Then there are homemade tricks that work pretty well.
My favorite is the magnet because it's the fastest — if it sticks, you already know it's fake.
There's also the unglazed ceramic test, rubbing it and if it leaves a real gold mark, it's a good sign.
Vinegar also works; genuine gold doesn't change color.
And well, weight never fails — real gold is dense and heavy, fake ones feel light.
But if you want to be 100% sure how to tell if it's quality gold, it's better to take it to a professional jeweler.
They have certified equipment and won't deceive you.
By the way, karat is what matters most: 24K is almost pure but very soft, 18K is the perfect middle ground (shiny and durable), and 14K is more resistant for rings and things you wear every day.
The lower the karat, the more resistant.
The higher, the purer.
It's worth learning this before investing in gold.