Historically a very expensive ground lazurite pigment, synthetic pigment has been used since the 1830's making it one of the most popular and affordable blues, Yves Klein blue is mostly Ultramarine. (Series 2)

Pigment Classification: Synthetic Inorganic
Color Index Name: PB 29
Color Index Number: 77007
Chemical Description: Polysulfide of Sodium-Alumino-Silicate
Opacity/Transparency: 6
Lightfastness Rating: I
Permanency: Not for exterior use
Munsell Notation Listing: Hue 8.0 PB Value 2 Chroma 4.5
Gloss Average: 23.89
Viscosity Range: 23000- 27000 CPS
CIE L*a*b* Values: L*24.36 a*12.28 b*-25.74
Tint Strength: 79.94