Geology Word of the Week: Carat

You may have noticed that I have been posting these geology words of the week on all different days. My original goal was to post them every Friday– that has rarely worked out, but I figure as long as I post a word on average once a week then all is good in the Evelyn Skepchick world. I post when I can in-between meetings, labwork, writing, and other graduate student tasks. One of my thesis advisors calls his students “gradual students.” I think this name is very appropriate. When I think about all that I need to accomplish in order to write my PhD thesis, I become entirely overwhelmed. However, if I take my thesis one task at a time, gradually working my way through, then I am able to keep my sanity.

Okay, on to this week’s geology word of the week: carat.

Def. Carat:
1. A unit of weight used for gemstones, equivalent to 0.2 grams.
2. Something Paris Hilton has in abundance.
3. Something bunny rabbits eat… oh wait, that’s carrot. Sorry.

Carat is also one of the “Four Cs” used in the gemstone world to set the price of diamonds and other stones. In general, the bigger the stone (the more carats), the more a diamond (or any gemstone) is worth. Of course, other considerations are important as well. A gigantic diamond that has a ghastly yellow color and contains ugly inclusions will not sell for a very high price. The three other Cs used in the gemstone (especially the diamond) world are: color, clarity, and cut. In terms of color, clear diamonds are generally worth more than yellowish diamonds. Unless, of course, the diamond has a “fancy” color. Colored diamonds are rare and often worth much more than regular white diamonds. Diamonds can be all colors of the rainbow- blue, green, red, even black! The third C for Clarity refers to the “clearness” of a diamond. Almost all diamonds have some inclusions or small cracks in them. The clearer or more “flawless” the diamond, the more it is worth. The final C is for Cut, which refers to the quality of the manmade cut of the diamond. The cut of a diamond is often overlooked but is actually very important- a beautiful natural stone can have its beauty (and its price) enhanced or reduced depending on the cut.

I have heard a fair amount about “the Four Cs” since I started dating a diamond geologist. As I wrote in one of my very first skepchick posts, I am not a big fan of De Beers or of the traditional diamond engagement ring. I wrote this post about six months before I met Mr. Diamond. We met at sea in June 2007. Well, technically we were still in port in Thailand at the time, but we shortly departed land to spend 50 days in the middle of the Indian Ocean in order to study a chain of underwater volcanoes. This cruise was part of a research project I worked on during my first two years of graduate school before switching to my thesis work in Oman. Mr. Diamond was an undergraduate (scandal… I was a first year graduate student) at the University of Cape Town. He was also a bursar with De Beers, meaning that De Beers was paying for four years of college and that he would be required to work for them for four years in order to pay them back. Not a bad deal, I suppose. I guess it’s sort of like a De Beers ROTC except that you don’t have to shoot anyone. Except pirates, maybe, if they attack your diamond-mining vessel.

Speaking of pirates, after about 49 (okay, maybe 48… it took him about two days to fall head-over-heels for me) days of subtle and not-so-subtle flirtation, Mr. Diamond and I had our first date: pirate watch. That’s right, our first “date” was pirate watch. After spending nearly two months in the Indian Ocean, we cruised past the volcanic island of Krakatoa (the very first land we saw!) and then up the coast of Sumatra. This region is known for piracy, so in addition to the normal watches taken by the crew, the scientists were given watch shifts as well. A day or two before we made it to our end port of Singapore, Mr. Diamond asked somewhat shyly if I’d like to sign up for the same pirate watch shift as him (scientist shifts were in pairs) from 4 am to 6 am. As Mr. Diamond now knows very well, I am not a morning person. However, because I was gradually (gradual student… get it?) admitting that I liked Mr. Diamond, I agreed and dragged myself out of bed at about 3:59 am for pirate watch. We spent two hours perched on the high back deck of the ship, passing night vision goggles back-and-forth and scanning the water for pirate vessels. We spent the two hours talking, the first time we really had an opportunity to talk alone since on a ship there is little privacy. I never would have expected on that first, rather unusual date that I would still be dating Mr. Diamond. Meeting and falling in love with him was a great surprise.

Mr. Diamond still works for De Beers, but I suppose I should call him Mr. Gold now since he now is working on finding gold for De Beers, which is (finally) starting to diversify since diamonds are not selling very well because of the poor economy. He actually has a fantastic job- he travels all over the world prospecting for offshore gold, which De Beers eventually hopes to start mining in the same way they currently mine diamonds offshore using the somewhat ironically-named ship Peace in Africa. He was hired for this position on a Tuesday and on the following Sunday they send him to New Zealand for two months. Not such a bad deal!

A little over a year ago, Mr. Diamond/Gold (I guess he was Diamond then) proposed. Well, we sort of proposed to each other– because we were in such a long distance relationship we decided we either needed to break up or get married. So we decided to get married. Whoever proposed to whom, though, the end result was that at the very end of one of my visits to South Africa Mr. Diamond took me to a Cape Town beach with a gorgeous view of Table Mountain, kneeled down, and pulled out a stunning 1 carat peridot ring. I said yes. I am very excited about my 0.2 grams of olivine, but I’m even more excited about marrying a wonderful, skeptical, handsome, cute (ever heard a South African accent?) geologist. We’re going to have many geological adventures together.

By the way, we became engaged on Friday the 13th of March. We only realized that we became engaged on Friday the 13th a couple of days later when a friend asked Mr. Diamond why in the world he decided to propose on that day. As a skepchick, I personally think our Friday the 13th engagement date is auspicious.


Evelyn is a geologist, writer, traveler, and skeptic residing in Cape Town, South Africa with frequent trips back to the US for work. She has two adorable cats; enjoys hiking, rock climbing, and kayaking; and has a very large rock collection. You can follow her on twitter @GeoEvelyn. She also writes a geology blog called Georneys.

Related Articles


  1. 4am watch? I never had a chance!

    Congratulations! :)

    BTW, just yesterday a friend was asking me about carats and silver “law” (in Spanish, the term for quality of silver, which is a number such as 0720, or something). Of course, I didn’t know a thing, so I now avoid talking with anyone if there’s no internet available!

  2. congratulations :) that is a beautiful peridot, i’ve always loved the stone for its unmistakable color (plus i’m born in august). of course, the first time i mustered up the courage to ask a department store clerk at the jewelry counter to show me a “pehr-i-dahT”, she kindly said, “Yes, the peri-dooos are right over here.” I was embarrassed at the time, but 20 years later, I have incorporated her style for subtly correcting people’s grammar without humiliating them.

  3. Congratulations, and a awesome post as well. I visited the Cullinan mine last year, I was quite surprised that there are black diamonds. They had some in the store there, and I will probably buy a ring that incorporates one someday.

  4. Congrats…

    And if you are feeling overwhelmed keep in mind that throughout your postdoc career onward you’ll think of the grad student time as “the good ol’ days”. It never gets any better, actually gets a lot move overwhelming.

  5. Congrats! What a beautiful ring!! And there are pirates in the story, well, at least peripherally.

    Gradual school… ugh, the perfect name for it.

  6. Thanks, everyone! By the way, we got engaged March 13th 2009. We haven’t figured out when we’re actually going to get married yet… we’ve both been busy with travel and such. Sometime, probably after I graduate. Or when I need health insurance.

    @kevinf: oh no! Don’t tell me things like this. They make me want to leave academia for industry! I just learned the other day that at many places (such as where I’m a grad student) postdocs are not given maternity leave. They certainly want to make it easy to balance work-family life, don’t they?

  7. Let’s here it for the non-diamond-solitaire engagement ring! ;) I got a yellow sapphire myself, though peridot got much consideration too. Love it.

    Great story! Puts my whole “met on IRC” one to shame. No pirates or anything.

  8. I hate to be pendantic, but carat is also used for purity. In the US we spell it “karat” to be distinct, but “carat” is the older spelling, which is still used in much of the world.

    Also, awesome ring. (Aren’t guys allowed to appreciate hyper-symbolic bling?) I too am a fan of not having a big central diamond. Diamonds make better condiments to our eyes. I once bought a girl a nice sapphire set with two smaller diamonds, and it was a good choice. (The ring, not the girl.)

  9. Damn! All I can say is that I want to die of envy. Your love story even has pirates in it! Simply awesome!! Congratulations!!

    Great post!

  10. Congratulations on getting married. My daughter Robin was born on friday 13th (june, 2008).
    All the best!

Leave a Reply

This site uses Akismet to reduce spam. Learn how your comment data is processed.

Back to top button