NGC Encapsulation & Conservation 3

Question 1

What does NGC's 'Conserved' designation indicate on a coin label?

Accepted Answer

Professional conservation was performed to stabilize or improve the coin's condition

Answer

NGC's 'Conserved' label designation indicates that professional conservation services were applied to the coin, which is disclosed transparently to buyers.

Question 2

Which environmental factor is MOST damaging to silver coins in long-term storage?

Accepted Answer

Hydrogen sulfide in the air causing toning and corrosion

Answer

Hydrogen sulfide reacts with silver to form silver sulfide, the primary cause of toning, dark spots, and corrosive pitting on silver coins.

Question 3

What is 'coin whizzing' and why does it negatively affect an NGC grade?

Accepted Answer

Rapidly spinning a coin to simulate luster, which creates artificial hairlines

Answer

Whizzing involves using a wire brush or tool to spin the coin's surface to fake mint luster, leaving fine raised lines that graders detect as artificial.

Question 4

In NGC conservation standards, what is the difference between 'cleaning' and 'conservation'?

Accepted Answer

Conservation stabilizes a coin using reversible methods; cleaning removes original surfaces

Answer

Proper conservation uses reversible, non-destructive methods to stabilize a coin, while cleaning often removes original metal or surface patina irreversibly.

Question 5

Why is acetone sometimes used in professional coin conservation?

Accepted Answer

It removes organic residues like tape, glue, and oils without harming metal surfaces

Answer

Acetone is a solvent that safely dissolves organic contaminants such as adhesive residue, fingerprints, and organic films without reacting with coin metals.

(NGC) Numismatic Guaranty Corporation Certified Professional Practice Test

(NGC) Numismatic Guaranty Corporation Certified Professional Practice Test

NGC Encapsulation & Conservation 3