"CTF" is the brand seal of Chow Tai Fook, but some products may use the "CTF" seal to show their relationship with Chow Tai Fook, but in fact it may not be the real Chow Tai Fook. Therefore, if you are considering buying diamond earrings or other jewelry, I suggest you carefully compare different products, including price, quality, brand reputation and other factors, before making a decision.
If you are in doubt about specific products, you can consult a professional jewelry appraisal agency or seek expert advice in other related fields.