This is 70 carats Natural Panjshir Emeralds for lapidary artists.
Buying loose emeralds most times depends on what you are looking for. You can get loose emeralds from reputable gemstone dealers. Platforms like Gemselect are not a bad idea to source these gems from. Local jewellers with strong and ethical sourcing backgrounds are not a bad idea either. No matter where you decide to purchase from, it is important you get a proper certification for authenticity.
Emeralds are worth buying firstly for their rarity and beauty.
Secondly, for their value which is dependent on quality, size, and origin. Therefore, emeralds are more valuable than other gemstones, so properly understanding these factors helps make the right choice.