Since then I’ve heard much discussion on the topic of precious vs. semi-precious gems and here is my belief. Historically, “precious gems” is a list that contains diamonds, rubies, sapphires, and emeralds. The "semi-precious" group of gems would contain more varieties such as; amethyst, citrine, quartz, turquoise, to name only a few.
I believe there are a group of "semi-precious” stones that do not fit that grouping based on their rarity and price per caret. For instance, Tanzanite is a very limited and beautiful stone that is highly sought after. This stone, when AAA blue, is more per carat than almost all precious gems. Color changing gems are another group that bears discussion. Gems like Alexandrite (June’s birthstone), Andesine, and some Garnets are very special and unique given that a color change is perceived based on the light source. I am lucky to have a handful of Andesine in my collection that are green when viewed under natural light and when a pen light is placed over them they look ruby red! It is quite amazing. I also have an Alexandrite that appears a deep emerald green to almost a royal purple dependent on the light source.
Gems that are bi-colored should also be considered when talking about categorizing precious vs. semi-precious stones differently. I believe that gemstones that show a unique attribute are and should be worth more in terms of value per carat and collector value. Due to this uniqueness I think the “semi-precious” connotation is inadequate. Even Ametrine (half amethyst and half citrine) can be extremely beautiful and be valued higher than other semi-precious stones. I am lucky enough to have collected an 11.2 ct. IF spectacular Ametrine.
I’d like to suggest that another grouping be introduced between the precious and semi-precious genres. It would be beneficial to include a group that more accurately reflect the desirability of these wonderful gemstones by encompassing the true preciousness of the gems over and above the current grouping system.
