Rublev malachite, from Natural Pigments, is shown on the left. Zecchi malachite scuro (dark), from Zecchi's Art Supply in Florence, Italy is on the right. Both dry pigments are ground in linseed oil. I have been hoarding the Zecchi color since I bought it in Florence in 2003. It is darker and richer than most other products and was invaluable in painting the first 2 pieces for the upcoming Pharaoh Part ll project.
The Rublev pigment is a splendid subtle bluish green and easy to grind. Both have a medium to low color saturation so you really have to pile on the paint to get good results. This pigment was commonly used by artists in ancient Egypt.