LESSON 12 Flashcards
A single or series of surface punctures, holes or gaps, made
by a sharp tool or created by an animal. The size is generally of
millimetric to centimetric scale.
perforation
Point-like millimetric or sub millimetric shallow cavities.
pitting
Generally coherent accumulation of materials on the surface.
crust
crust sub types:
- black crust
- salt crust
Kind of crust developing generally on areas protected against direct rainfall or water runoff in urban environment.
black crust
Crust composed of soluble salts, which develop in the presence of high salt levels, and form from wetting and drying cycles.
salt crust
Accumulation of exogenic material of variable thickness. Some
examples of deposits : splashes of paint or mortar, sea salt aerosols,
atmospheric particles such as soot or dust, remains of conservation
materials such as cellulose poultices, blast materials etc.
deposit
Change of the stone color in one to three of the color parameters: hue, value and chroma.
discoloration
discoloration - Change of the stone color in one to three of the color parameters:
- hue
- value
- chroma
corresponds to the most prominent characteristic of a color
(blue,red, yellow, orange etc.).
hue
corresponds to the darkness (low hues) or lightness (high hues)
of a color.
value
corresponds to the purity of a color.
chroma
discoloration sub types:
- coloration
- bleaching
- moist area
- staining
change in hue, value and/or a
gain in chroma
coloration
gain in value due to chemical weathering of
minerals (e.g. reduction of iron and manganese compounds) or
extraction of coloring matter (leaching, washing out), or loss of polish,
generally very superficial.
bleaching
