A gem possesses the factors of naturalness, beauty and rarity. This order can also be viewed as an increase in value. We assume naturalness. There are many natural but unsightly stones. The precious stone must also be beautiful, but it can also occur relatively frequently.
Now for rarity: a value is substantial when we have comparability. The comparability decreases with higher rarity, but a few absolute values are sufficient to make a comparison. This value will be higher, and often exponentially higher, as the stone becomes rarer.
WHAT EXACTLY IS THE RARITY?
This is the geological rarity of the type of stone, i.e. the mineral, and the 4C of this type of stone in combination. The rarer one of the 4Cs in a stone is, usually due to geological reasons, the higher its investment potential as long as the stone is beautiful. This beauty depends on the color, hardness (i.e. polish) and light refraction (indirectly the sparkle). So investment colored gemstones must meet the requirements of a gemstone, but far beyond that, have a rare 4C combination and great market acceptance, i.e. “beauty”. In addition, there is a large possible passive marketing, historical value and possibly also the origin from a specific supplier country.
OF INCREASING IMPORTANCE FOR INVESTMENT COLORED GEMSTONES IS CERTIFICABILITY.
Laboratories that issue stone reports must be equipped with up-to-date and state-of-the-art equipment. In addition, gemstones should not be easy to produce synthetically, nor should their detection be particularly complex. For example, synthetic emeralds are commercially available, but these are often easy to detect. Thus, security is maintained on the market.