enow.com Web Search

Search results

  1. Results from the WOW.Com Content Network
  2. Marble - Wikipedia

    en.wikipedia.org/wiki/Marble

    Marble is a metamorphic rock consisting of carbonate minerals (most commonly calcite (CaCO 3) or dolomite (CaMg (CO 3) 2) that have recrystallized under the influence of heat and pressure. [1] It has a crystalline texture, and is typically not foliated (layered), although there are exceptions. In geology, the term marble refers to metamorphosed ...

  3. Conservation and restoration of shipwreck artifacts - Wikipedia

    en.wikipedia.org/wiki/Conservation_and...

    Iron and copper oxides can penetrate deep into the pores of ceramics and stones and create reddish-brown to black stains (iron oxide) and blue-green stains (copper oxides). The use of EDTA salt solution can be used to remove the oxides. A mild solution consists of 3% to 5% of EDTA; 15% to 20% solution in water on ceramics to remove the stains.

  4. Marble sculpture - Wikipedia

    en.wikipedia.org/wiki/Marble_sculpture

    Marble is a metamorphic rock derived from limestone, composed mostly of calcite (a crystalline form of calcium carbonate, CaCO 3).The original source of the parent limestone is the seabed deposition of calcium carbonate in the form of microscopic animal skeletons or similar materials.

  5. Black oxide - Wikipedia

    en.wikipedia.org/wiki/Black_oxide

    Black oxide or blackening is a conversion coating for ferrous materials, stainless steel, copper and copper based alloys, zinc, powdered metals, and silver solder. [1] It is used to add mild corrosion resistance, for appearance, and to minimize light reflection. [2] To achieve maximal corrosion resistance the black oxide must be impregnated ...

  6. Chemical coloring of metals - Wikipedia

    en.wikipedia.org/wiki/Chemical_coloring_of_metals

    Chemical coloring of metals is the process of changing the color of metal surfaces with different chemical solutions. The chemical coloring of metals can be split into three types: electroplating – coating the metal surface with another metal using electrolysis. patination – chemically reacting the metal surface to form a colored oxide or salt.

  7. Iron oxide - Wikipedia

    en.wikipedia.org/wiki/Iron_oxide

    Iron oxide pigment. The brown color indicates that iron is at the oxidation state +3. Green and reddish brown stains on a limestone core sample, respectively corresponding to oxides/hydroxides of Fe 2+ and Fe 3+. Iron oxides feature as ferrous or ferric or both. They adopt octahedral or tetrahedral coordination geometry. Only a few oxides are ...

  8. Malachite - Wikipedia

    en.wikipedia.org/wiki/Malachite

    Malachite is a copper carbonate hydroxide mineral, with the formula Cu 2 CO 3 (OH) 2.This opaque, green-banded mineral crystallizes in the monoclinic crystal system, and most often forms botryoidal, fibrous, or stalagmitic masses, in fractures and deep, underground spaces, where the water table and hydrothermal fluids provide the means for chemical precipitation.

  9. Copper(I) oxide - Wikipedia

    en.wikipedia.org/wiki/Copper(I)_oxide

    Copper (I) oxide or cuprous oxide is the inorganic compound with the formula Cu 2 O. It is one of the principal oxides of copper, the other being copper (II) oxide or cupric oxide (CuO).The compound can appear either yellow or red, depending on the size of the particles. [2] Cuprous oxide is found as the mineral cuprite.