Ultramarine Blue is an inorganic Mineral Pigment. Chemically it is a SODIUM ALUMINO SULFOSILICATE. The typical chemical analysis of medium Ultramarine Blue is SiO₂-37%: Al₂0₃-28% : S-14%: NA₂O-19% 
Specific gravity: 2.35 gm/ cm3. 

The tap density varies between 0.5 kg/1 per for the clearer type and 0.8 kg/1 for the darker ones. It has been classified in the color index with the reference: PIGMENT BLUE : 29.C.1.77007

OIL ABSORPTION: The values of oil absorption oscillate between 36 and 40 grams of oil (Linseed Oil) per 100 grams of blue, depending on the nature of the Blue pigment and the level of micronization. Generally the darker shade types have lower absorption than the lighter shades.

TINTING STRENGTH: Tinting Strength is a relative concept which indicates its capacity to tint an opaque material that contains another pigment in its formulation. Ultramarine Blue is an inorganic pigment and thus has moderate tinting strength. It depends on two basic parameters. Particle size and the correct formation of the structure of the Ultramarine Blue (adequate positioning of the sulphur in the crystal structure). In general terms, it can be said that dark blues (large particle size) have lower tinting strength and lighter blues (particle size close to one micron) have a greater tinting strength.

SPECIFIC SURFACE: The values of our Blue range from 3 to 12 m2/gm.

OPACITY: Ultramarine Blues are transparent when dispersed in oleoresins and plastics given that their index of Refraction (1.51.) is close to that of the vehicle, One can take advantage of the half transparency of the Blue to achieve attractive transparent colors. To obtain opaque colors, small quantities of Titarium Dioxide must be added.

DISPERSIBILITY: Ultramarine disperse easily in water based media, in oils, resins and plastics. With more micronizing of the pigment and a softer texture it is easier to disperse the pigment reaching a fineness of 10 microns in paints and eliminating all the non - dispersed pigment particles in plastics.

SOLUBILITY: Ultramarine Blue is insoluble in all aliphatic and aromatic solvents and will not migrate in paints, inks, or plastics.

ACID RESISTANCE: Ultramarine Blue has very little acid resistance although it does resist attack by aluminum sulfate.

TEMPERATURE RESISTANCE: Technical grade Ultramarine Blue maintains its color and properties in plastics processed at 350 C for 5 minutes and in certain cases it has good resistance in temperature above 400 C.

MOISTURE CONTENT: Even though it absorbs some moisture, its hygroscopic power is weak. Ultramarine Blue easily acquires a balanced humidity which depends on atmospheric conditions, which can be quantified between 0.5% & 1.5% depending also on particle size and atmospheric humidity. Moisture content of the micronised type is in general lower than 1.3%. In Laundry grade type it is lower than 1.0%.

LIGHT RESISTANCE: Ultramarine Blues have excellent light resistance, rated at 8 on the Wool scale. Naturally, the pigment incorporated in resins and polymers which may have poor fastness will be affected by light.

ALKALI RESISTANCE: Ultramarine Blues have good alkali Resistance. At PH = 8.0 it performs well, but, at higher alkalinity, its resistance diminishes in relation to the time in contact with the alkaline solution. For instance it can last for two hours at PH = 9.00 without alteration but after 2.5 hours it starts, a color weakening, changing towards a green dirty shade. Normally an alkaline resistance of PH - 8 is adequate for inks and paints of neutral final product.

SAFE PIGMENTS: Ultramarine Blue has been used over the last 150 years without causing any safety or hygienic problem. It is completely ATOXIC and gives negative bacteriological, TERATOGENIC and mutagenic toxicity results.