Ochre was derived from the Greek word ohkar-meaning pale yellow, pale is a natural earth pigment containing hydrated iron oxide, which ranges in colour from yellow to deep orange or brown. It is also the pigment produced by this pigment, especially a light brownish-yellow. A variant of ochre containing large amount of hematite or dehydrated oxide has a reddish tint known as red-ochre.
Ochres being friable are crushed and lixiviated, just like china-clay, to obtain extremely fine-textured material of uniform colour. Refining by elutriation followed by drying often improves both iron content and colour.
The principal use of ochre is as tinting colours. It is used for colour washes, distemper and oil paints. Red oxide pigments are widely used as primers for painting structural steel, automobile bodies, ship bottoms, etc.
Ochre is a natural earth containing silica and clay tinted by hydrous forms of iron oxide, such as yellow-brown limonite or brown-yellow to green-yellow goethite, and traces of gypsum or manganese carbonate. Limonite is a general term used to describe all forms of hydrated iron oxide minerals (FeO(OH)) that occur as natural clay or earth.
Ochre absorbs a medium amount of oil. It slows the drying of oil paint, but forms an excellent film.
Gold ochre is a natural earth containing clay tinted by hydrated iron oxide, such as yellow-brown limonite or brown-yellow to green-yellow goethite.
Warm red ochre is a natural earth containing clay tinted by hydrated iron oxide that gives an exceptionally warm orange red hue.
Ochre is not considered toxic, but care should be used in handling the dry powder pigment to avoid inhaling the dust.
During the 1970s, Red and Black Oxide Floors were all the rage in Kerala. Malayalis called it- ‘Kaaviyidal’. These days, red oxide floors have made a return with many improvements.
The Red/ Black oxide powder is mixed with white cement and applied to the floor. Even with the best materials and finishes, the estimated cost is less than Rs.15 per sq. ft, making it a value-for-money choice!
For Red Oxide flooring the flooring oxide and cement are mixed in the ratio of 1:3 to 1:5 by weight/volume. This mixture is made into a thick slurry with water and applied for cement flooring, wall and steps.
For mosaic flooring first of all, mix the Red oxide with white cement, chips and white powder in dry powder form. After mixing the above items well, and a little water and mix them thoroughly. Again add more water according to your requirement.
A thin coat of this coloured paste is applied evenly on the floor. The floor is soaked continuously for next 3-4 days under water column. After complete setting, the floor is polished for best results. The use of colours other than Red, Yellow, Black and Chocolate for exteriors should be avoided. Acids should never be used for cleaning or polishing. One’s imagination should be applied to create colourful patterns in interiors.
100 to 150 Sq. feet per Kg for flooring top finishing with cement slurry and color oxide (color oxide and cement ratio 1:5). However varies with the thickness of the top finishing and the type and color of the cement used.
The flooring colours are mixed thoroughly with grey or white cement in 1:8 ratio by weight. Colour to cement ratio may be varied to get deeper or lighter shade of a particular colour. Best results achieved when white cement is used.
A consistent and slightly thick paste with water is prepared, taking care to mix well. A thin coat of this coloured paste is applied evenly on the floor.
This type of flooring is good for health. This tradition is available in Kerala. In Tamilnadu also in the interior villages this flooring is done. But the attraction is not towards this flooring even though the cost is very low when compared to polished granites, tiles etc.