Alabaster
Alabaster (also called satin spar) is a natural crystalline mineral of hydrated calcium sulfate mined near Volterra (between Florence and Sienna), Italy. Softer than chalk (3 Mohs scale of mineral hardness), its hardness of 1.5 to 2 makes a soft white gesso that is easier to polish to a smooth finish for gilding bases and painting grounds. Calcite or chalk, being a carbonate, effervesces on exposure to acids, whereas gypsum alabaster, when so treated, remains practically unaffected.
Recommended in Cennino Cennini's treatise on painting, Il libro dell'arte (often translated as The Craftsman's Handbook), to make "gesso sottile" for painting grounds.
Add to oil colors and mediums as a transparent filler and to give body or in tempera as a white filler.
Source
Tuscan alabaster occurs in nodular masses embedded in limestone, interstratified with marls of Miocene and Pliocene age. The mineral is worked largely by means of underground galleries, in the district of Volterra.
| SKU | 510-11ALB |
|---|---|
| Brand | Rublev Colours |
| Vendor | Natural Pigments |
| Processing Time | Usually ships the next business day. |
Health & Safety: There are no acute or known chronic health hazards with the anticipated use of this product (most chemicals are not thoroughly tested for chronic toxicity). Protect yourself against potentially unknown chronic hazards of this and other chemical products by avoiding ingestion, excessive skin contact, and inhaling spraying mists, sanding dust, and concentrated vapors from heating. Contact us for further information or consult the SDS for more information. Conforms to ASTM D-4236.
