CAMBRIDGE, Mass. — The first blue pigment to hold its color was often prized over gold. The semi-precious stone lapis lazuli was ground into an iridescent pigment, sometimes called ultramarine, that ...

Lapis lazuli is a vividly blue rock, sometimes with streaks of gold, that has been known for millennia for its eye-popping colour and use as a semi-precious gemstone. It gets its colour from the ...