Sodalite is a chlorine-bearing feldspathoid that usually forms aggregates of small crystals, and is 6 on the Mohs scale. Sodalite also occurs as a minor constituent in the mineral aggregate Lapis Lazuli, which would account for why they are so similar in colour.

In gemstone folk law, Sodalite is said to increase confidence, enhance creativity, and have a balancing effect on emotions and mental state.

The Mohs scale of hardness was devised by a German mineralogist called Frederich Mohs (1773-1839) in 1812. He selected the ten most commonly readily available minerals to show the difference in hardness of each. The scale runs from 1-10, 1 being the softest, and 10 being the hardest.

THE MOHS SCALE

Talc = 1
Gypsum = 2
Calcite = 3
Fluorite = 4
Apatite = 5
Orthoclase = 6
Quartz = 7
Topaz = 8
Corundum = 9,

and this includes sapphire and ruby, and they are twice as hard as topaz, even though it is only one number more on the Mohs scale of hardness.

Diamond = 10

thereby being the hardest mineral mined. It is four times harder than corundum, even though it is only one number more on the Mohs scale of hardness.