1, general. Although Taishan black diamond is unique and rare, it can still be found in the market, and it is not the only rare mineral. Taishan black diamond has a specific geographical and cultural value in Taishan, China, but it is not so special in the world.

2. Low weight. Compared with precious stones such as diamonds, rubies and sapphires, the hardness grade of diamonds may be better, but it does not have much advantage in market demand, practical application and return on investment. It doesn't have enough driving force for consumers to flock to it, which leads to its lower price. In addition, its application in jewelry industry is relatively limited, mainly used for ornaments and decorations, so its actual value is lower than that of some rare minerals with wide application value.