Any questions? Need help shipping your items?
Call us at (NEW) PHONE# COMING UP Mo-Fr 8am to 8pm EST
or email us at

Sitemap  |  Contact  |  Privacy Policy  |  Terms & Conditions P3M Refining, your 100% Canadian owned and operated Gold Buyer.
We buy gold, silver and platinum jewellery, dental gold, old gold. P3M Refining Ltd., the gold buyer of your choice.
What we buy

Carat (purity)

The carat (abbreviation ct or kt) is a measure of the purity of gold alloys. In the United States and Canada, the spelling karat is used, while the spelling carat is used to refer to the measure of mass for gemstones. As a precious metal and gold buyer, respectively we buy gold scrap, jewellery, dental gold with a purity of 6KT and higher. For plated gold and gold alloys with a low gold content refer to our "Special Items & Commercial Customer" section.


To convert the purity carat/karat into percentage use the following simple formula: 100/24*X where X is the carat rating of the material. Therefore 24-carat gold is fine (99.9% gold is accepted as 24KT although using the formula it should of course be 100%), 18-carat gold is 75% gold, 12-carat gold is 50% gold, and so forth. Historically, in England the carat was divisible into four grains, and the grain was divisible into four quarts. For example, a gold alloy of 381/384th fineness (that is, 99.2% purity) could have been described as being 23-carat, 3-grain, 1-quart gold. The carat system is increasingly being complemented or superseded by the millesimal fineness system in which the purity of precious metals is denoted by parts per thousand of pure metal in the alloy.

The most common carats used for gold in bullion, jewellery making and by goldsmiths are:

  • 24 carat (millesimal fineness 999)
  • 22 carat (millesimal fineness 916)
  • 20 carat (millesimal fineness 833)
  • 18 carat (millesimal fineness 750)
  • 15 carat (millesimal fineness 625)
  • 14 carat (millesimal fineness 585)
  • 10 carat (millesimal fineness 417)
  • 9 carat (millesimal fineness 375)
  • 8 carat (millesimal fineness 333)
  • 1 carat (millesimal fineness 042)


The word carat is derived from the Greek kerátiōn (κεράτιων), "fruit of the carob", via Arabic qīrāṭ (قيراط) and Italian carato. Carob seeds were used as weights on precision scales because of their reputation for having a uniform weight.(However, a 2006 study by Lindsay Turnbull and others found this to not be the case - carob seeds have as much variation in their weights as other seeds.) This was not the only reason. It is said that in order to keep regional buyers and sellers of gold honest, a potential customer could retrieve their own carob seeds on their way to the market, to check the tolerances of the seeds used by the merchant. If this precaution was not taken, the potential customer would be at the mercy of "2 sets of carob seeds". One set of "heavier" carob seeds would be used when buying from a customer (making the seller's gold appear to be less). Another, lighter set of carob seeds would be used when the merchant wanted to sell to a customer. In the distant past, different countries each had their own carat, roughly equivalent to a carob seed. In the mid-16th century, the Karat was adopted as a measure of gold purity, roughly equivalent to the Roman siliqua 1/24th of a golden solidus of Constantine I). As a measure of diamond weight, from 1575, the Greek measure was the equivalent of the Roman siliqua, which was 1/24th of a golden solidus of Constantine; but was likely never used to measure the weight for gold.

Gold items
Areas we serve

P3M Refining Ltd. is based in Barrie, Ontario and we are a 100% Canadian owned and operated Company. Of course Ontario is not the only area we serve. We hope to be the platinum, silver & gold buyer of your choice in all of the following Canadian areas.

Newfoundland and Labrador NL, Nova Scotia NS, Prince Edward Island PEI, New Brunswick NB, Quebec QC (Eastern, Western & Northern), Metropolitan Montreal, Ontario ON (Eastern, Central, Southwestern, Northern), Metropolitan Toronto, Manitoba MB, Saskatchewan SK, Alberta AB, British Columbia BC, Nunavut and the North West Territories NT, Yukon YT