Bone ash is made from selected bones properly leached, ground, chemically treated, calcined by a special procedure and milled to a small particle size. Our bone ash is obtained by roasting degelatinized bone up to a temperature of approximately 1100° C. Afterwards, the bone ash is cooled and ground to a fine particle size so that a minimum of 95% will pass through a 325-mesh (U.S. Standard) sieve. The excellent properties of bone ash is attributed to the internal structure of the small, individual particles. The original cellular structure of the bone is preserved, thus giving the material a high resistance to heat transfer (natural thermal insulator). Bone ash is primarily tri-calcium phosphate or a form of calcium hydroxyapatite.
Bone ash has the following intrinsic properties:
Has excellent non-wetting properties
Is chemically inert and free of organic matter
Has high resistance to heat transfer (natural thermal insulator)
In painting grounds, it makes a durable surface while adding some tooth especially for egg and casein tempera, distemper, encaustic and oil painting. Use in chalk and gesso grounds to increase absorbency and add texture. Bone ash is used in Cennino’s recipe for silverpoint grounds.
Add to oil colors and mediums to create textural and bodying qualities to oil paint without affecting the color. Bone ash has little color in drying oil, so it can be added to oil paint without affecting the color temperature.
How to Use
Put half of the required water together with all the bone ash powder in a container. Add enough water to get a good mixing action. Continue mixing until lump free and uniform consistency is obtained. Do not vortex the mixture in order to avoid air entrainment. Add the remaining water as required by the formula or recipe.
Ash from calcined and degelatinized bone ground to 325 mesh
Typical Chemical Analysis
Tri-Calcium Phosphate (Ca3 [PO4]O2)
Calcium oxide (CaO)
Magnesium oxide (MgO)
Carbon dioxide (CO2)
Silicon oxide (SiO2)
Iron oxide (FeO)
Aluminum oxide (AlO)
Typical Physical Properties
Retained on 325 Mesh Screen
Loss on Ignition @ 1100° C.
Apparent Bulk Density, Packed
Apparent Bulk Density, Loose
Natural Pigments is a limited liability company based in Willits, California. We manufacture and distribute rare and hard-to-find materials for fine artists and decorators. We specialize in supplying artists' materials that were used in historical painting since pre-historic times up to and including the nineteenth century.
We constantly search for materials and products of the finest quality so that we can bring them direct to you from the source. To do so, we travel the world to find materials specifically for use by professional artists and decorators. We obtain minerals from mines in Afghanistan, Chile, Russia, Ukraine and Uzbekistan, to name a few places, processing these into natural pigments. We purchase resins, gums and plants from India, Kenya and Malaysia to make natural varnishes and painting mediums.
Our mission is to provide the largest variety of natural pigments, paints and other professional artists' supplies, enabling us to bring you a selection that makes shopping for rare and hard-to-find art materials easy. Our objective is to promote the education and use of these materials among artists by providing detailed information for their employment in encaustic, fresco, oil, watercolor and tempera painting.
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This product is shipped from our warehouse in Gretna, NE, USA.
This product is brand new and includes the manufacturer's warranty, so you can buy with confidence.
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