Jewelry Blog

>About The Measurement System
Gemstone hardness is measured on the Mohs scale. This is a relative scale so you can understand which gems are harder than others. The Mohs scale is not proportional. For example, a gemstone with hardness of 6 is not twice as hard as one that is hardness 3. However, you can tell how easily a gems will be scratched. For example, this system is great for telling which gems will scratch other gemstone jewelry.
Mohs Hardness Scale
Here is a chart from hardest to softest of the most common gemstones used in jewelry. Some stones have a range so this chart is approximate in those cases.
Hardness —- Gemstone
10 ———— Diamond
9 ————- Ruby, Sapphire
8.5 ———– Alexandrite, CZ
8 ————- Topaz, Spinel
7.5 ———– Aquamarine, Emerald, Garnet, Tourmaline
7 ————- Amethyst, Citrine, Iolite, Quartz
6.5 ———– Peridot, Tanzanite, Zircon
6 ————- Moonstone
5.5 ———– Opal, Lapis
5 ————- Apatite, Obsidian
4 ————- Flourite, Malachite, Platinum
3 ————- Coral, Pearl
2.5 ———– Amber, Gold, Silver
What Does The Mohs Scale Tell You
Besides telling you how easy a stone scratches, it tells you how brittle a stone is and how fragile a stone is. Often soft stones should not be used in rings as they will be damaged too easily. Note that gold, silver and platinum are softer than most gemstones and as such can easily be scratched. More info here