If you don't it will tarnish.
all metals have lustre i think
If they are not being used, I would reccoment once a year.
Yes, and no depending on the state of the coin. (clean, shiny, polished)
Copper Proof means that the coin is made from copper and that it has been struck on specially prepared and polished dies. Proof coins are often hand finished giving it a mirror like surface.
Copper can have a rough texture depending on its form and treatment. In its raw state, copper may appear rough and uneven due to oxidation and impurities. However, when polished or processed, copper can have a smooth, shiny surface. Overall, the texture of copper varies based on its condition and usage.
A ball door knob described as "polished brass" is typically made of brass, a metal alloy primarily composed of copper and zinc. The term "polished brass" refers to the finish of the door knob, indicating that the surface has been meticulously polished to achieve a smooth and shiny appearance. infinitydecor.co.uk/product/ball-door-knob-polished-brass/
For fancy dining, the cutlery (knives) are often polished and should always be sharpened properly. Flatware should always by polished (with a clean dry cloth) to remove water spots. Silver should be polished with a paste of baking soda and water, rinsed clean, dried and polished as above.
You can make lacquered copper antiques look new again by washing the item in warm, soapy water with a non-abrasive towel. You can make unlacquered copper antique look new again by scrubbing the item with a salt covered lemon until all the tarnish is gone. The item should then be rinsed, dried, and polished.
One physical property shared by gold, copper, and iron is their metallic luster. This means they are shiny when polished or freshly cut.
We do not know. Copper was discovered before we had writing to keep records. People have used copper for about 6,000 years.
Well, since 1992 all Great Britain 2 Pence coins have been made of copper-plated steel. This is a very thin layer of copper and harsh/vigorous polishing (especially with abrasive powders) can easily remove this coating. I gently polished a 2 pence piece with a soft cloth and it did not become silvery but remained that rosy color of new copper.
Yes, the copper of the penny acts as a fungicide. You should also add vinegar to the water to help make the water more acidic.