ASTM D765-87 pdf free.Standard Specification for Raw and Burnt Sienna Pigments.
The pigments shall conform to the following requirements:  Raw Sienna- The pigment shall be in a soft, dry form and shall be a hydrated oxide of iron permeating a siliceous base. The pigment shall conform to the requirements for composition prescribed in Table 1.
Burnt Sienna- -The pigment shall be produced by the calcination of raw sienna and shall conform to the requirements for composition prescribed in Table 1.
Paste in Oil- -For both raw and burnt sienna, the paste in oil shall be made by thoroughly grinding the pigment with linseed oil (with or without a small amount of volatile thinner) together with (where necessary) small amounts of wetting or dispersing agents to produce a paste or semipaste of satisfactory consistency. As received, it shall not be caked in the container and shall break up readily in linseed oil to form a smooth paint of brushing consistency. It shall mix readily in all proportions, without curdling, with linseed oil, turpentine, or volatile petroleum spirits, or any mixture of these substances.
The mass color and character of the tint and the tinting strength formed by a mixture with a white pigment shall be within mutually agreed upon limits of a standard acceptable to both the purchaser and the seller.
Two samples shall be taken at random from diferent packages from each lot, batch, day’s pack, or other unit of production in a shipment. When no markings distinguishing between units of production appear, samples shall be taken from different packages in the ratio of two samples for each 5 tons (inch-pound or SI), except that for shipments of less than10 000 lb two samples shall be taken. At the option of the purchaser, the samples may be tested separately or after blending in equal quantities the samples from the same production unit to form a composite sample.
Tests shall be conducted in accordance with the appropriate ASTM test methods. Test procedures not covered by ASTM test methods shall be mutually agreed upon by the purchaser and the seller.ASTM D765 pdf download.