Porosity: Areas of the mold that absorbed some of the casting material leaving the cast object with a rough, granular surface.
Porosity
Porosity refers to the areas of the mold that absorbed some of the casting material and leaves the cast object with a rough, granular surface.
Pot Metal ...
To reduce the porosity, Turquoises are poured into epoxies or acrylic resigns or other substances, so that these are infused into the pores of the turquoise to form a solid turquoise.
The stone's porosity and low-luster make it a good candidate for enhancement — magnesite is often dyed to resemble much-pricier turquoise.
This may be done to produce colors not usually found in nature, to improve color, to improve clarity, to reduce porosity and stabilize color (by preventing absorption of discoloring oils and other substances), or to enhance durability.
In general, a high proportion of silicate minerals increases hardness and decreases porosity while a high content of clay minerals (like kaolinite) has the opposite effect. On one end of this spectrum, then, we find pieces of hardness 5.
'Glassy carbon' is isotropic and contains a high proportion of closed porosity. Unlike normal graphite, the graphitic layers are not stacked like pages in a book, but have a more random arrangement.
Hydrophane - a porous potch exhibiting a weak play of color only when wet. Its porosity causes it to adhere to a moist surface.
Hyalite - a colorless transparent glassy potch.
During casting, impurities can sometimes be introduced into the molten metal, leaving weaknesses in the ring when it solidifies. (Known as porosity).
Comet Tail
A surface defect in metal, that only becomes evident during polishing, caused by an inclusion or porosity in the metal ...
Chlorine can cause stress corrosion cracking in lower gold alloys of 14 carat and below, although it will be worse if the jewellery contains porosity through less than perfect manufacturing treatments.
The metal is melted as rapidly as possible to reduce the evaporation of low-melting-point metals in the alloy and to prevent the inclusion of oxygen, which can add to the porosity of the metal.
Stabilized Turquoise: Turquoise is very porous by nature which allows it to absorb any pollutants that it comes in contact with, including oils from the skin. Stabilized turquoise has been treated by various methods to reduce the porosity, ...
Emeralds are a beautiful addition to anyone's jewelry collection, but they should be worn with care. Emeralds are not to be cleaned in ultrasonic cleaners because of their porosity.
American turquoise color will fade faster han the Persian turquoise because it has a higher porosity and is more absorbant.
porosity The percentage of a soil, rock, or sediment's volume that is made up of pores. porphyritic Describing a rock that contains large, noticeable crystals, usually feldspars.
Stabilized TurquoiseA process by which the stone is treated by various methods to reduce the porosity, thus making less changeable. Sterling Silver925 parts silver, legal standard.
 See also: Jewel, Color, Water, Stone, Surface
  
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