Cerridwen Greenleaf, author of The Magic of Crystals and Gems, has written a new blog post where she explains all of the different categories of precious and semiprecious gems, crystals, and stones.

First, let’s explain the different categories: precious and semiprecious gems, crystals, and stones. We’ll start with the widest category, stones, which actually encompasses all the other categories. Stones can hold much magic and bring the best to you. I’m always looking in my path for a pretty stone or one of an unusual shape or coloration. In fact, I have a mobile altar in my car that is frequently augmented by a charming chunk of rock. I always notice that my friends and passengers are unable to resist picking them up and rubbing the smooth surfaces admiringly. Maybe one day, I’ll find a diamond in the rough in my path!
Stones have been of interest for many centuries. Primitive peoples probably picked up stones out of curiosity. Through trial and error, they discovered which rocks withstood the test of time and were more durable for use in tools. Doubtless, they also noticed that some stones could be polished to a lovely sheen.
Stones are primarily minerals that can be defined as natural, generally inorganic substances with a chemical composition and an internal atomic structure. So, a diamond, the most precious of all in the eyes of many rock hounds, is a stone and also a crystal with a very simple structure of one element—carbon. Quartz, a very commonly available and rarely expensive stone, is usually referred to as rock crystal and is composed of two elements—silicon and oxygen. Crystals are defined as such because of their internal diffracting patterns—that is, by the way they hold and reflect light. Rocks can be defined as natural, solid compounds of mineral grains, or glass, or a combination of both.
What is the difference between precious and semiprecious gems? The simple distinction between these two categories is that only the most rare and costly gems are classified as precious. Emeralds, rubies, sapphires, and diamonds fall into this foremost category. Those remaining gems, such as opal, amethyst, and bloodstone, are semiprecious. Gems are a special class of very valuable minerals rated according to their hardness, color, and luster. Gems are held so dear because of their quality; they are usually clearer, rarer, and exquisitely beautiful.
All of these “rules” date back thousands of years in some cases. There is great tradition surrounding the lore and love of gems, stones, and crystals. They are simply glorious. Think about it—not only are they lovely to look at and to adorn yourself with, but they also have properties that bring love, health, happiness, abundance, and peace of mind.
The magic of crystals and gems
Unlocking the Supernatural Power of Stones (Healing Gemstones and Crystals)
Practice Practical Magic: Did you know that wearing an amulet of green jade on an interview will help get the job? Have you heard that an amethyst ring can help break bad habits and even encourage sobriety? Anyone looking for love can place two pink quartz crystals in the bedroom; you’ll not be alone for long! These are just a few of the hundreds of secrets shared in The Magic of Crystals and Gems. Semi-precious stones and gems have long been known for their magic as well as their beauty. In this book of charms, readers learn everything there is to know about the powers of crystals from birthstone magic to gem divination to jewelry spells. This is a fun, entertaining, and enlightening book that will appeal to everyone who’s ever worn a birthstone, kissed the ring of a lover for luck, or bought a crystal for good energy.