Opal and amber are not minerals.
Yes, like the mineral Quartz is also a gem.
its an mineral
a diamond is a mineral (also is a gem)
A sapphire gem is mainly composed of the mineral corundum and other trace mineral impurities that give it its color.
Gem
Yes.
No, nickel is a mineral.
The web address of the Houston Gem And Mineral Society is: http://www.hgms.org
The web address of the Fallbrook Gem And Mineral Museum is: http://www.fgms.org
a gem
Opal and amber are not minerals.
gem