Amethyst
Photosensitive, the color will fade if left in strong sunshine. It is recommended not to be left in the sun, except for short periods of cleaning or preparation of elixirs.
Apatite
Sensitive to acid exposure – an unlikely event in crystal therapy, but worth mentioning.
Calcite
It may be affected by water, so it is better not to be put in water for cleaning or cleaning.
The rough calcite usually has a smooth waxy texture, it can be immersed in water without problems and is often used to make an elixir.
Some varieties, particularly honey calcite, are photosensitive and will lose their color if exposed to the sun for a long time.
The calcite is also soft and easy to scratch.
Chrysocolla
It is a very soft crystal (hardness 2-4), therefore it scratches lightly. It is advisable to handle it especially as a jewel where it is quite exposed to possible scratches.
Pink Quartz
Some pink quartz crystals are photosensitive and will lose color if left in strong sunshine.
Being quite difficult to know which pink quartz will be affected and which is not, it is recommended to keep any quartz pink away from the sun’s rays; obviously except for short periods of purification and cleaning or for the preparation of elixirs.
Copper
Contains minerals that are slightly soluble such as malachite and azurite.
For elixir solutions use dioptase, chrysocolla and other copper-containing silicates
* and are safe to be non-soluble.