Gemstone vs Ground Is Lava

How close are they?

ΔE 9.3, close: similar, with a visible difference side by side. Ground Is Lava is a little lighter, more muted than Gemstone.

Can I use Ground Is Lava instead of Gemstone?

Usually, if you are not matching paint already on the model. Close match (ΔE 9). Ground Is Lava is a little lighter, more muted than Gemstone.

Can I use Gemstone instead of Ground Is Lava?

The same difference applies the other way round: Gemstone is a little darker, more saturated.

ΔE is the colour difference between our two swatch estimates: under about 6 is close, over about 15 is loose. Real paints also differ in finish, coverage and how they thin, so test before you commit.