Understanding Different Types Of Gold Karat
Write a short note on karat and fitness.
Answer:
Karat:
- It is also known as carat.
- It is the parts of pure gold in 24 parts of alloy, for example, 24 karat or 24K gold is pure gold (100%).
- 22 karat gold: 22 parts pure gold (91.67%) and 2 parts of other metals.
- An alloy with 50% gold is l2 K, whereas an alloy with 75% gold is 18K.
- The carat system is commonly applied to dental casting alloys.
Fineness:
- Fineness is the actual gold content in gold pieces.
- It is expressed in grams or troy ounces.
- Karat weight is a unit of fineness for gold equal to 1/24 part of pure gold in an alloy.
- Pure gold which is 1000 fie is 24 Karat and finess of 750 is 18 Karat.
- The finess is obtained by multiplication of the mass percentage of gold by l0.
- It is the parts per 1000 of pure gold, for example,
- Pure gold: 10000 files.
- 750 fie gold: 75% gold content
- Used to describe gold alloy soldiers.
- The symbol for fitness is F.
Powdered Gold As A Restorative Material
Write a short note on powdered gold.
Answer:
- Powdered gold is also known as granular gold or encapsulated powder gold or EZ gold.
- It is known as EZ gold because its manipulative characteristics are similar to, a very stiff amalgam and is more sticky than gold foil.
- Powdered gold is a blend of atomized and precipitated powder that is embedded in a wax-like organic matrix.
- The average particle size of powdered gold is 15 µm.
- As a powder the material is impractical to manipulate, so is gathered into a conglomerate mass having a diameter of 1–3 µms.
- These masses are either sintered or lightly condensed to facilitate slight adhesion between the particles and ease of handling.
However, even on mild provocation, these masses tend to fall apart:
- This is available in pellets of various sizes which are mixed with wax and are enclosed in gold foil no. 3 wrappers and packed for their usage.
- The usage of pellets of powdered gold increases cohesion at the time of compaction and decreases the time needed for placing the restoration.
- Commercially available pellets of powdered gold wrapped in a gold foil are known as Golden.
- The ratio is 95% powder and 5% foil.
- It is provided in a cohesive form. The powdered particles are mixed with soft wax and held in a No. 3 gold foil.
- The gold foil acts as a container for the powdered particles and facilitates their condensation.
- Each pellet contains approximately ten times more gold than a pellet of gold foil of comparable size.
- The hand method of compaction is better than mechanical compaction for powdered gold.
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