The wife loses a stone; the husband blames the wife; the wife blames
the jeweler; the jeweler blames the manufacturer; the manufacturer
looks for an answer. Hoover & Strong answers the question. What
causes most prong breakage? Chlorine and bromine. Where does it come
from? Hot tubs, swimming pools and laundry products. Hoover & Strong
has conducted a controlled experiment to determine the effect of
common chlorine and bromine products on jewelry settings. We tested
household bleach, (heated and unheated), hot tub chlorine and
bromine solutions, and a chlorine free dishwashing detergent. We
tested 14K and 18K nickel white settings; set and unset, rhodium
plated and not plated; palladium white gold and platinum settings.
Hoover & Strong’s testing rates their products from the most durable
to the least durable as follows: Platinum; rhodium plated 14K
palladium white gold, 14K palladium white gold; rhodium plated
nickel white gold, 18K nickel white gold; and 14K nickel white gold.
Chlorine and bromine are commonly used chemical products to prevent
bacteria from growing in our drinking water, in swimming pools and
hot tubs. Too much of these compounds added may cause a human health
threat and a durability problem for settings. The higher the
concentration, the longer the exposure and the higher the
temperature, the faster the deterioration of the settings.
Stress occurs in metals when they are worked. Stress can be relieved
in metals by proper heat treating. A simple experiment to
demonstrate this can be performed by bending a paper clip until It
breaks off, count the number of times you bend the paper clip. Next
bend the same paper clip just short of its breaking point. Heat the
paper clip to a cherry red and let it cool. This IS called
annealing. Now bend the paper clip and count the number of times you
have to bend it before it breaks. The annealing relieved the paper
The test solutions are listed in order from the product causing the
most damage to the least harmful. The rings soaked in heated bleach
suffered the most catastrophic failure. The 14K nickel white gold
was the first to fail in all solutions except the household
detergent. The household detergent had little or no effect on the
rings or settings. The test was stopped when the first setting
failed and all items were compared. Based on our testing, a consumer
wearing a 14K nickel white gold setting would lose a stone or expect
prong breakage as follows:
Results Of Each Solution
5% chlorine bleach heated to 110F, prong failure would occur
after 21 hours of exposure. Only the platinum and palladium white
gold settings held their stones in the worst test solution.
5% chlorine bleach room temperature -prong failure would occur
after 120 hours of exposure.
5 ppm (parts per million) chlorine using hot tub chemicals-prong
failure would occur after 312 hours or 156 days.*4’, 5 ppm (parts
per million) bromine using hot tub chemicals-prong failure would
occur after 384 hours or 192 days. *
Household detergent -no visible effects on the setting.
Hoover & Strong’s recommendations: Use platinum settings, 14K
palladium white settings. Rhodium plate 18K or 14K white settings,
the rhodium plating will provide a protective coating to protect the
setting; similar to paint stopping rust.
Last but not least, tell your customers not to wear their jewelry in
hot tubs and swimming pools. Take jewelry off when using laundry or
cleaning products. NEVER, NEVER clean rings with bleach. Suggest
that they bring them to you for cleaning and a checkup, just like
going to the dentist to have their teeth cleaned and checked.
- based on 2 hours a day, 7 days a week
Hoover and Strong