With the little bug's eyes looking at the opals up close, the surfaces of the gemstones were revealed to be not very smooth. The surfaces had some very, very small holes, which made them look like the surface of the ground after the soil had been struck by raindrops during a rainstorm.
Looking further inside, black dust spots could be seen. The biggest selling point of an opal was the gorgeous change in colors. However, the insides of the gemstones were lifeless and not gorgeous at all, as if the patterns were inlaid.
It took a type of intuition. Looking at the gemstones after having seen a lot of natural fire opals made it easy for Li Du to realize the difference between the two.
In addition, the inside and outside of a natural opal was consistent and had homogenous colors linked by a natural color transition layer. When looking slowly along the opal, the change in colors was not noticeable.
