what physical properties would make calcite a poor choice for a gemstone?

Answer 1

It is brittle, so it would be hard to shape, it only has a hardness of three (barely harder than a fingernail), and easily dissolved in solution. Plus, it's too common! Gemstones need to be rare to be valuable.

Answer 2

Gemstones should be beautiful, rare and durable. Calcite can be lovely, but it isn't very rare. However, the two main reasons that make calcite a poor choice for a gemstone are:

1) It is a very soft stone. It is only 3 on the Mohs Scale of hardness, which means it will be very vulnerable to daily wear and tear.

2) It cleaves easily and perfectly in 3 directions. Hit it in the right spot and you'll see a cube-like section break off your gemstone! It's a very interesting property of calcite, but not one that you will appreciate in a gemstone.

Another minor reason - calcite has a very high birefringence. When cut as a faceted stone, the back facets will appear doubled when viewed from the table. This makes the stone look sleepy, affecting brilliance considerably.

Answer 3

Gemstones are nearly always much harder than everyday materials (the only common gemstone that is softer than glass is opal). Using glass as your hardness cutoff (5.5 on mohs hardness scale) any mineral harder than this would be a candidate for a gemstone based on hardness. Calcite's hardness on the scale is only 3. If you had a ring with a calcite stone it would be abraded and eventually destroyed as it came in contact with every day materials

Answer 4

It's really soft and dissolves in Hcl. It would eventually dissolve in rain water!

Answer 5

calcite will disintegrate if anything acidic touches it--it will not be immediately but it will occur