Crystals and gemstones are classified by several ways.
The 3 PRIMARY ways are by their HARDNESS, TOUGHNESS and MINERAL GROUPING ( the chemical composition of the mineral)
A MINERAL’S HARDNESS
The hardness of a mineral / crystal has to do with its “scratch resistance” or ability to be scratched by other minerals / objects. Harder minerals can scratch softer minerals.
The strength of the bonds between the atoms in the crystal is the main thing that determines the hardness of a mineral.
Some minerals have a varying hardness. For example, kyanite has a different hardness depending on whether it is measured along its elongated grains or counter to its grain.
Every crystal has its own hardness or range of hardness. The most widely used method of measuring a crystal’s hardness is the Moh’s Mineral Scale of Hardness.
The Moh’s scale was devised by Friedrich Moh’s in 1812 and its range is from 1 – 10, although there are minerals that have a hardness greater than 10.
The following is a list of 10 common crystals and their hardness number. The majority of the crystals are somewhere in the 4.5 to 7.5 hardness range.
2 Gypsum (Selenite family)
6 Feldspars (Including Labradorite, Sunstone, Moonstone)
9 Corundum (Ruby and Sapphire)
Here are the hardness of some non crystalline objects: Our fingernail is approximately 2.5, the old copper pennies are approximately 3.5, a glass window is 5.5 and a steel file is about 6.5.
A MINERAL’S TOUGHNESS
The toughness of a mineral refers to its resistance to breaking, being fractured, chipped or cracked when exposed to a high impact hit or fall. The mineral’s molecular structure (grainy, density, compactness and interlocking) plays a key part in determining its toughness.
To better understand hardness versus toughness, let’s compare a diamond to nephrite jade (the 2nd most tough naturally occurring mineral).
Even though diamonds are a 10 in hardness, they are not terribly tough. With normal day to day wear, they can crack and chip.
Jade, on the other hand (approx. 6.5 hardness), is very tough and will not easily crack or chip. When a diamond and jade are hit hard, the diamond will split and the jade will bruise.
Jade’s toughness is why it is often carved, sawed and made into beautiful objects of art.
THE DIFFERENCE BETWEEN CRYSTALS, GEMSTONES, MINERALS, ROCKS, NATURAL STONES AND TUMBLES…
A crystal is a solid material made up of atoms (or groups of atoms), ions and/or molecules which are naturally arranged in a regular repeated pattern. As is the case with many crystals, these patterns are exactly the same and consistent throughout the entire crystal. Many crystals are composed of quartz (silicon dioxide) along with tiny pieces of other minerals.
Gemstones are minerals or natural materials composed of different chemicals. Generally, gemstones refer to rare and beautiful minerals that are durable enough to be cut and polished and made into jewelry. Gemstones can be semi precious or precious based on their rarity, appearance and method in which they were mined.
A mineral is any substance which always has thesame chemical composition. Minerals can contain combinations of elements, salts, sulfur and silicates. Their composition is usually crystalline in structure due to geological occurrences in the Earth.
ROCKS / STONES:
Rocks, AKA stones, are ANY composition of 2 or more minerals. Rocks DO NOT have any SPECIFIC chemical composition. They are formed from naturally occurring combinations of dense minerals or mineral like substances which have been exposed to mother nature for many years. Rocks are classified by their chemical composition, appearance and their natural growing and formation process.
Some folks prefer crystals in their raw (natural) form while others prefer crystals that have been polished (tumbled) or made into jewelry.
ROUGH / RAW / NATURAL STONES
Rough stones are stones that remain in their natural condition, never subjected to human workmanship. Some believe that raw stones have the greatest amount of healing power. Crystals placed directly on the body provides the greatest amount of healing. Of course, if the crystal is too rough, it may be more advisable to use polished stones.
TUMBLED / POLISHED STONES
Tumbled stones are stones that have been placed along with sand and water in a tumbling machine or drum. These stones are often tumbled for days making them smooth. Stones found around lakes, rivers and oceans can also become smooth from the water and sand hitting up against them over time. Polished and tumbled stones are perfect for placing directly on the body or held in the hand for crystal healing.
Before crystals and stones are made into jewelry, they must be cut, shaped and polished.
Some of the most elegant and magnificent jewelry is incorporated with gemstones. Jewelry doesn’t need to be made with precious stones (ie: ruby, sapphire, diamond) to be striking. Tiger eye, with its chatoyance, in a nice setting can make a gorgeous piece of jewelry. The way in which jewelry is made and the person making the jewelry can impose a positive or negative influence on the stone. Gemstone jewelry is not only beautiful to look at, it can be extremely functional. Wearing or donning a crystal pendant, ring, necklace, bracelet or anklet can reap positive benefits.