Everything in the immediate area surrounding your jewelry affects it. Everything.
What you store your jewelry in is an accurate predictor for the occurrence of tarnish as well as the extent of its severity. For instance, many people think that storing their jewelry in the packaging it arrived in is safe, but that’s not always true.
Materials such as cardboard, papers and foams can contain sulfides, which are the primary catalyst for silver tarnish. Not only do these materials contain sulfide innately but often times they absorb sulfide and other reactive gases in transit and distribution.
It’s no surprise that jewelry tarnishes when coming in direct contact with materials containing tarnish-causing compounds.
However, it’s important to note that materials not in direct contact with your jewelry can cause tarnish as well. More specifically, wood and jewelry showcase materials.
Let’s take a look at how different species of wood, wood treatments and components of jewelry showcases can cause jewelry tarnish.
Ah, wood. Nothing is more organic than that! There’s no way wood could contain corrosives, right?
Unfortunately, this notion is FALSE.
Believe it or not, wood can be extremely acidic – containing acetic acid in particular.
Corrosion of metals caused by wood is a known phenomenon and a substantial amount of research has been conducted to identify the least acidic types of wood.
As a matter of fact, manufacturers and commercial builders have been dealing with this problem for decades:
“Wood is a corrosive substance by nature, and can be made more corrosive by treatment given to it. Unlike most other corrosive substances, one of the corrosive chemicals in it, acetic acid, is volatile, and in an ill-ventilated space, wood can cause corrosion of metal nearby but not actually in contact”
Source: National Physics Laboratory
What does this have to do with jewelry? Well, more often than not, jewelry is stored in wooden jewelry boxes. Here’s why it’s a problem…
Acetic acid is corrosive, “most metals are attacked by acetic acid, which can cause corrosion at concentrations as low as 0.5 ppm in air. Serious damage can occur through long-term storage, especially in damp conditions”.
Its rate of emission from wood depends on its species, the temperature and its moisture content, while its rate of escape into the atmosphere depends on the geometry of the wood (e.g. its internal structure).
Luckily, some of the aforementioned research conducted on the corrosive properties of wood has yielded some helpful information! Because the rate of formation and emission of acetic acid largely depends on the species of wood itself, pH charts have been created indicating which strains of wood are the least acidic and contain the least amount of corrosives:
So when it comes to choosing the species of wood your jewelry box is made of, these relative levels of acidity are important to keep in mind.
Okay, so I should store my silver in a jewelry box made with of a lower-acidity wood. Problem solved, right?
Unfortunately, (once again) that isn’t the case. Even if you use a species that’s been found to contain lower amounts of acetic acid, you’re still not out of the woods, yet...