Under Construction, August 2011

Abrasion: Surface wear caused by friction, often resulting in a change in optical properties.

Accretion: A process of growth or build-up from external addition. A build-up of something on the surface of an artifact from external sources.

Arsenic: A toxic element that is commonly found as an oxide and used in pesticide preparations, particularly for taxidermy mounts.

Bloom: A white haze or crystalline growth that can be found on many surfaces, including leather, wood and paint. It is often attributed to free fatty acids migrating to and crystalizing on the surface. Synonyms: Blush, Fatty Spue (or Spew), Chill, Efflorescence. Often confused with mold or salt efflorescence.

Borax: a salt of boric acid, soluble in water, widely used in detergents, cosmetics, putties, pesticides, fluxes and many other applications.  Synonyms: sodium borate, sodium tetraborate, disodium tetraborate.

Byne’s Disease: a white efflorescence formed on seashells, eggshells, or snail shells (shells formed of calcium carbonate) that are exposed to acetic and formic acid vapors – commonly off-gassed from wood.

Calcined: Oxidized by heating.

Crizzling: A fine network of cracks on the surface of glass caused by…?.

Cutin: Waxy, water-repellent polymer found in the plant cuticle that covers the external surfaces of plants. See also suberin

Delamination: the splitting of a material into layers.

Dendritic: needle-like

Devitrification: A change in glass composition from vitreous to crystalline form. This causes clear glass to lose its transparency.

Dressing: Fats, oils or waxes applied to leather in an effort to help it maintain flexibility.

Efflorescence: White, powdery, crystalline crust that is formed from salts that migrate to the surface of a material in an aqueous solution and crystalize through evaporation of the water. Typically found on ceramic, stone or plaster surfaces. Synonyms: bloom, encrustation. Can be confused with fatty bloom and mold.

Exudate: Something that oozes out from a material.

Fatty Spue (or Spew): see Spew and Bloom.

Fruiting Bodies: The microscopic ball-like formations found at the end of some of the branched structures of mold when it is ready to reproduce.

Ghosting: Transfer of an image by substances that ooze or bloom out of a material and deposit on an adjacent surface.

Glass: typically a translucent or transparent material composed of a mixture of silicates. Often has other additives such as lead, uranium, phosphate or an alkali material to alter the physical properties of the glass.

Glass Disease:  A break-down of the silicate structure of glass, largely due to improper ratio of ingredients during manufacture and worsened by improper environmental conditions. This is often associated with 16th century Venetian glass production, but can be found in glass from many time periods and places of production. Symptoms include cracking or crizzling of glass, the formation of liquid on the surface (weeping), delamination, devitrification, and white crust formation. Synonyms: Sick glass, weeping glass, crizzling. In beads, referred to as “Bead Disease.”

Haze: A cloudy or transparent-looking white stain

Hyphae:  long, branching filament like structures of a fungus

Kaolin: Calcined clay, sometimes used to whiten leather during manufacture or use.

Keratin: fibrous protein that forms the chemical structure of hair, nails/claws, baleen, horn, hoof and feathers.

Labile: likely to change or alter

Leather: Can be used to refer to a variety of products made from the skin of an animal, such as chamois, hide, parchement, rawhide, sinew, suede, or vellum. Produced by a wide range of tanning methods (see Tanning). 

Lipid: a general umbrella term for fats, oils, and waxes that are not soluble in water.

Mechanical Damage: Damage caused by physical forces like abrasion, bending, scraping, cutting etc as opposed to chemical damage, for example.

Mold: A living organism produced by fungus. Often described as “fuzzy” or “wooly” in appearance. Typically found in damp conditions (>70% RH) on organic surfaces. Synonyms: Mildew, Mould.

Mycelium: the part of a fungus that features a mass of branching thread-like arms (hyphae)

Patina: A corrosion product or surface alteration that is desirable to keep due to its pleasing appearance, historical or or protective value.

Spew: Often specifically refers to the waxy white exudate that forms on leather. See Bloom.

Suberin: A waxy waterproof substance present in the cell walls of cork tissue in plants.  See also cutin.

Sweating: liquidy ooze that comes to the surface of a material, usually referring to oils coming out of leather or less commonly weeping glass.

Tanning: the chemical process that converts skin into leather. There are numerous processes for this, including vegetable, brain, alum, smoke, synthetic, and chrome.

Tideline: The darker edge of a circle or irregular shape without angular edges that forms when a liquid containing dissolved materials evaporates from a surface and leaves a concentrated residue of those materials behind.

Tin pest: A fragile white powdery material formed as tin changes from one allotrope form to another at temperatures below 56 degrees Fahrenheit.

Weeping: When salts form on the surface of glass as the result of glass disease, they attract water and form droplets on the surface leading to a “weeping” appearance.

White Rust: A white tarnish that forms on zinc. Synonyms: Zinc Bloom.

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