Diamonds ARE rare.
According to the Merriam-Webster Dictionary, something is rare when it is seldom occurring or found-uncommon. If this is the definition upon which rare is measured, then diamonds certainly qualify. Most diamonds are an average of 3.2 billion years old.
Diamonds Need Precise Conditions
It is the way that nature creates diamonds that make them valuable and rare. Diamonds begin as carbon buried deep within the Earth’s mantle. The carbon is only transformed into a diamond under precise temperature and pressure conditions. Once a diamond is created within the Earth’s mantle, it can only rise to the surface through a volcanic eruption. Even then, it has to rise to the surface through the volcanic magma rapidly enough to ensure that it does not convert to graphite during the ascent. Once it reaches the surface, it can then be mined.
The Mining Process Produces Very Few Quality Diamonds
The diamonds are ready to mine, which would seem a very profitable endeavor. Unfortunately, it takes a vast amount of resources and finances to find the quality diamonds. One million grams must be mined to produce five grams of diamonds. Of those five grams, only 20% are considered ‘of gem quality’. [“Diamonds”, nature.berkley.edu]
All these factors make diamonds a rare commodity.
“Diamonds.” College of Natural Resources – UC Berkeley. N.p., n.d. Web. 16 Nov. 2011. http://nature.berkeley.edu/classes/eps2//wisc/Lect6.html
“How Do Diamonds Form? | They Don’t Form From Coal!.” Geology.com: News and Information for Geology & Earth Science. N.p., n.d. Web. 16 Nov. 2011. <http://geology.com/articles/diamonds-from-coal/>.