Wednesday, July 25, 2007

What is a Carat?

You may have noticed that with most gemstone pieces here and on other sites like Belinda's, the "carat" weight of rubies, topaz or other gemstones are given.

So are these gemstone carats different from diamond carats ? And are carats and karats related?

Carats -- It's All About Weight
Simply put, a carat is a unit of weight for diamonds and other gemstones, although in the past, only diamonds were measured in carats. Diamond carats and ruby carats and rose quartz carats and emerald carats and all other gemstone carats are all the same. One carat is equivalent to 0.2 grams and each carat is divided into 100 points: for example, a 40-point diamond is 0.4 carats.

The greater the carat, the heavier the gemstone.

Carats do not refer to the dimensions (ie. how big/small it looks) of a gemstone. The dimensions of a gemstone are determined by a variety of factors, including cut.

Karats -- It's All About Purity
A karat is a unit of purity when used with gold. For example, 24-karat (or 24K) gold = pure gold. 14-karat (or 14K) gold = 14 parts gold, 10 parts some other metal.

For gold to be called gold legally, the lowest purity is 10 karats (10K).

And once again, even though gold-fill is almost as good as gold, it cannot legally be called gold, even if it is 14K gold-fill. (Technically, yes, you can get into trouble for referring to "gold-fill" as "gold", but that's another post for another day).

Useful links to check out (some sites where I got my info!):
http://www.wisegeek.com/what-is-a-carat.htm
http://www.diamondring.com/forums/diamondtutorial.php?learn=2
http://www.howstuffworks.com/question64.htm

Hope this helps!

4 comments:

Wan said...

Thank you for posting this Simone! I had been thinking about this for some time. Since 1 carat = 0.2 grams, do you think it will be accurate enough to weigh gems in grams and then do a conversion? I notice that some gem retailers weight them in grams instead of carats. So I assume that this is fine business-wise?

Simone said...

Good question, Wan. Honestly, I don't know. But logically, it makes sense, especially if the stone has been weighed accurately.

I must admit though that I haven't met a gem retailer who weighs their finer stones in grams instead of carats -- carats are the industry standard for gemstone weight, as far as I know.

I've met some which give you the weight both in grams and carats.

But I digress!

If you want to, and if you would get use out of one, maybe you'd like to get your hands on one of those weighing thingies -- available at professional jewellery supply shops (not the usual beading shops) and online?

Sorry couldn't help that much!

Anonymous said...

Wow, this is certainly Carat 101 for me. Thanks for sharing!

Simone said...

You're a gem, Karen ;) Thanks much!