If the back of the jewelry is marked something like "10k EMB cTo", sources suggest that "EMB" stands for emblem meaning that emblem is 10k, but item is embedded with another material.
"cTo" is the trademark used by O. C. Tanner Jewelry Co., Salt Lake City.
Of all the marks that could be on your jewelry, the one that tells the carat weight is probably the most important. Carat weight can be written in a variety of different ways, as there is no standard and each manufacturer has its preferred method. You can commonly see it written as 10k or .417 for 10 karat gold (either white or yellow). 14 karat gold may be written as 14k or .585 (again, either white or yellow).
Carat weights are the second most common stamp in a jewelry and indicate the weight of the diamond or jewel.
Solid gold jewellery is a purchase that you will be able to enjoy for life, even generations, so before you make a purchase it is wise to educate yourself on the different standards of gold available.
Here are some key facts everyone should know about gold before making a jewellery purchase and what to look out for as a shopper shared by Edgeonly.com.