Uncommon Elements Make Uncommon Gemstones

Why are some gems so rare in nature? Learn which elements in the Earth's crust are the rarest and how these ingredients help form uncommon gemstones.

Why are some gems more common in nature than others? Gemology teaches us that crystalline gemstones need five things to develop: ingredients, temperature, pressure, time, and space. Let's take a closer look at that first requirement.

Since the principal source of ingredients for gems is the rocky Earth itself, knowing the abundance of the elements that make up the minerals in the Earth's crust will help us understand why there are common and uncommon gemstones.

The Abundance of Elements in the Earth's Crust

From a gemological perspective, the following uncommon elements in the Earth's crust are of particular interest:

• Manganese (Mn) 0.095%
• Carbon (C) 0.02%
• Zirconium (Zr) 0.0165%
• Vanadium (V) 0.0135%
• Chromium (Cr) 0.01%
• Nickel (Ni) 0.0075%
• Copper (Cu) 0.0055%
• Cobalt (Co) 0.0025%
• Lithium (Li) 0.002%
• Beryllium (Be) 0.00028%

A World of Oxygen and Silicon:

Oxygen and silicon make up more than 74% of the Earth's crust. It's not surprising that quartz (SiO2) is one of the most common gemstone minerals.

However, oxygen and silicon are also found in some uncommon gemstones. Spodumene is a gemstone mineral composed of oxygen, silicon, aluminum, and lithium (LiAlSi2O6). Lithium makes up just two thousandths of 1% of the Earth's crust.

Kunzite, a pinkish variety of spodumene, gets its color from the addition of another uncommon element, manganese.

From Emery Boards to Uncommon Gemstones

Corundum (Al2O3) is a common mineral composed of aluminum and oxygen. You'll frequently find it on sandpaper and nail files as emery. Gem-grade corundum, however, is considerably more rare, even rarer than diamonds. Corundum gems that include a rare trace of chromium are red in color. This red variety of corundum is more commonly known as ruby. Chromium is just one hundredth of 1% of the Earth's crust.

Beryllium is less than three ten-thousandths of 1% of the Earth's crust but it's a primary ingredient of beryl gemstones (Be3Al2Si6O18). With the addition of chromium, another rare element, beryl becomes emerald.

Likewise, the gem species spinel takes on a very rare cobalt blue color with the addition of cobalt, another rare element.

The Rarity of Rare Elements

The rarity of these uncommon elements in the Earth's crust is a key factor in the scarcity of certain gemstones. Manganese, chromium, cobalt, beryllium, and lithium are all relatively rare in the overall composition of the planet. This means that the minerals and gemstones that rely on these elements for their formation and coloration are also quite rare.

In contrast, the more abundant elements like silicon, aluminum, and oxygen are found in a wide variety of common gemstones like quartz, feldspar, and corundum. These gemstones may be beautiful, but they are not as unique or valuable as the rarer varieties.

The Value of Rarity

The rarity of certain gemstones is a major factor in their value and desirability. Diamonds, rubies, emeralds, and other precious gems are prized not just for their beauty, but also for their scarcity. These gemstones are the product of uncommon geological conditions and the presence of rare elements in the Earth's crust.

In the gem trade, rarity is a key driver of price. The more rare and difficult a gemstone is to obtain, the higher its value will be. This is why some gemstones, like red beryl or painite, can fetch astronomical prices at auction, even for small specimens.

Appreciating the Uncommon

As we've seen, the rarity of certain elements in the Earth's crust is directly linked to the scarcity of certain gemstones. The uncommon ingredients that give rise to these precious gems are a testament to the incredible diversity and complexity of our planet.

Next time you admire a rare and beautiful gemstone, take a moment to appreciate the uncommon elements that came together to create it. These gemstones are not just beautiful, but also a window into the intricate workings of the Earth's geology. They are a reminder that even in a world dominated by the common, the uncommon can still be found, if you know where to look.