In the Western world, precious stones are diamonds, rubies, emeralds, and sapphires. Any gemstone other than these four is referred to as semi-precious, but that does not make it less valuable than precious stones. A rare or high-quality semi-precious gemstone can often be worth much more than a diamond! Semi-precious stones simply tend to be more abundant. Since the terminology leads to misconceptions about value, many people in the trade no longer adhere to the labels of precious and semi-precious, though they are still used by the general population.
Semi-precious gemstones often come in a variety of colors due to their abundance and are commonly used in jewelry. Some of the most popular semi-precious stones are garnet, peridot, amethyst, citrine, blue topaz, turquoise, malachite, and lapis lazuli.
The category of semi-precious gemstones is also misleading because several of the gemstones defined under this label are not actually stones at all, like pearl or amber. While many of them are a single mineral, like quartz, others like lapis lazuli are a combination of several minerals mixed together. Lapis lazuli is mainly composed of the azure lazurite mineral, but also contains calcite (which is white) and pyrite (which is gold). This is what gives lapis lazuli its beautiful blend of colors that often resembles a starry night sky.
Chile is one of the most abundant countries on Earth in terms of semi-precious stones, particularly in the Western hemisphere. In addition to lapis lazuli, the main semi-precious stones found in Chile are malachite, turquoise, jasper, quartz, and obsidian.
- Malachite is found in Chile's copper mines because the mineral is composed from various copper chemical compounds. Malachite's deep green color has been used in jewelry, ornaments, and even make-up in ancient times. It was also believed to protect against the "Evil Eye."
- Turquoise is formed from volcanic rocks, making it abundant in Northern Chile. It's color ranges from light blue to dark green, although the most valuable pieces are robin's egg blue. It is one of the oldest-mined gemstones, considered to be very valuable and have healing properties.
- Jasper is an aggregate of microquartz and other chemical compounds, which can range in color to red, brown, yellow, or green. The name is derived from Latin for "spotted or speckled stone" and it is known as the most popular gemstone in ancient times.
- Quartz is the second most common mineral on the planet. It comes in a variety of translucent colors, but the most valuable forms found in Chile are completely transparent. Quartz was identified as a mythical substance in ancient mythology, but has many practical uses today, particularly in electronics.
- Obsidian is a naturally occurring volcanic glass. It is used mainly for ornamental purposes as well as weaponry. Obsidian can make extremely sharp blades, some of which are even used by surgeons as scalpels (though not legally permitted for use on humans).
It is clear that the terminology distinguishing precious from semi-precious stones is not particularly useful in identifying the various rocks, minerals, and substances that fall under these categories. Each "gemstone" has its own unique properties and they often range widely in value . Their main common factor is their mesmerizing beauty and the fascination that cultures have placed on them over centuries.