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  2. Joel Samson

    8,000 carat natural black diamond from africa

    https://www.gia.edu/gems-gemology/summer-2017-carbonado-diamond It depends on porosity Porosity. As the porosity of an object increases, its apparent density decreases, because the voids take up more and more of the volume. In carbonado, the number of exposed micro­diamond cutting points increases with porosity. This was a sought-after property that made carbonado more expensive by weight than diamond at the turn of the twentieth century (Haggerty, 2014). Densities as low as 2.8 g/cm3 and as high as 3.45 g/cm3, with most around 3.05 g/cm3 (Trueb and De Wys, 1969; Haggerty, 2014), are in contrast to gem diamond at 3.52 g/cm3.
  3. Joel Samson

    8,000 carat natural black diamond from africa

    It depends on porosity Porosity. As the porosity of an object increases, its apparent density decreases, because the voids take up more and more of the volume. In carbonado, the number of exposed micro­diamond cutting points increases with porosity. This was a sought-after property that made carbonado more expensive by weight than diamond at the turn of the twentieth century (Haggerty, 2014). Densities as low as 2.8 g/cm3 and as high as 3.45 g/cm3, with most around 3.05 g/cm3 (Trueb and De Wys, 1969; Haggerty, 2014), are in contrast to gem diamond at 3.52 g/cm3.
  4. denverappraiser

    8,000 carat natural black diamond from africa

    It's perhaps worthy of note that the density of diamond is 3.51g/cm3, not 3.2.
  5. Joel Samson

    8,000 carat natural black diamond from africa

    OK sir thanks
  6. davidelevi

    8,000 carat natural black diamond from africa

    Hi Joel, welcome to Diamond Review! I think the first thing you should do is to find a gemmologist (relatively) local to you and confirm identification as a diamond; then you can think about incurring the significant expenses involved in getting the stone to a first-rate lab (GIA has labs in Hong Kong, Taipei - 2 hours flight away) and graded. 100% gem species identification from photos is effectively impossible, but some things can be ruled out, and I for one have severe doubts that what you have in the pictures is a diamond.
  7. Dear fellow members, I'm Joel from the Philippines,. I have a natural black diamond weighs is 8,000 carat single stone and density of 3.2g/cm,Luster is Metallic...,I hope someone can help me to certify my black diamond...Thank You.,.
  8. Earlier
  9. denverappraiser

    Knot in Diamond

    It sort of depends on what you mean by a very old stone. Diamonds, by their nature, are upwards of 200 million years, give or take a few. We don't know the history of this particular stone, and the jeweler probably doesn't either, but there are a few things we DO know. 1) On March 10, 2021 it was at GIA. It was undamaged at that time. 2) Faceted girdles are a relatively recent innovation in cutting. Recent stones are mostly all faceted girdles, and before 2000 or so, almost none were. 3) GIA-X doesn't usually just happen. The cutter deliberately cuts to those proportions because they want that grade. GIA didn't even define what those proportions WERE until 2006. All in, I think we can safely say that it's post-2006 cutting and that passed a GIA inspection in 2021. Depending on what you mean, that may still fall into 'old', but it makes me hate to admit how old I am.
  10. davidelevi

    Deciding on a Diamond - Need help!

    Definitely a good plan! Good luck, and let us know how you get on; hopefully you'll come out of the conversation with more answers, but if you have more questions instead, we are here to help.
  11. AC792

    Deciding on a Diamond - Need help!

    This is great context and I appreciate the insight. Moral of the story, I really need to see Diamonds side by side in the store. I am going in today to talk to the jeweler and I think I'll have them bring in a couple of SI2 and SI1 for comparison purposes. I will try to get more specs and post as well. Thanks!
  12. davidelevi

    Deciding on a Diamond - Need help!

    OK - so, looking at the example you just linked, here are three factors that will drive the price down: 1. Strong blue fluorescence (especially in a D colour) will depress price significantly. Whether that's 'relevant' to the aesthetics is a completely different question, but it will impact the price. We (on the forum) don't know if any of the first batch were fluorescent or not... but part of the difference may be there. 2. While this is an SI1, and the grade by itself will impact the price (meaning that the average SI1 will be more expensive than the average SI2, all else being equal), a much stronger price driver is whether the inclusions are visible to the naked eye. My bet is that the smattering of dark crystals under the table, reflected multiple times, would be easily visible and potentially bothering to quite a few potential buyers, hence a low(er) price. Again, we don't know whether the inclusions in the SI2s you listed in the first post are as easily visible or much less so. 3. Cavities - especially multiple ones - are definitely not a 'desirable' characteristic. They may not be a big issue in terms of durability or integrity, and here the larger ones are on the pavilion, which means they'll be less visible to a 'normal' observer, but they do depress the price. The question of cut is moot... the RC diamond seems to be an OK cut (and I personally like the shape), but the way in which the video is taken seems to be largely to show inclusions, rather than brilliance, sparkle and fire. Plus, of course, we don't have videos for the others to compare (to the extent that it is possible with videos taken by different vendors).
  13. AC792

    Deciding on a Diamond - Need help!

    That is fair. For example, I see this on Rarecarat: Rare Carat® | Search and Buy Diamonds at Online & Local Stores. This seems to be a better grade and clarity than the ones I was quoted, and for less $. Again, I realize the ones I was quoted could potentially be excellent cuts, etc. So it's a hard comparison.
  14. davidelevi

    Deciding on a Diamond - Need help!

    Hm. Be careful. There isn't anything 'special' about the diamonds on Rarecarat (or on Blue Nile, for that matter), and that is a global market - if people are offering 'much better' prices for the same grade or 'much better' grades for the same price, something is amiss. (If for 'much better' you mean a difference of $4-500 on a $10k stone, then everything is fine, but differences of more than a few % are suspect).
  15. AC792

    Deciding on a Diamond - Need help!

    Thank you for the feedback. After doing a bit more research, it looks like I can find much better grades on Rarecarat. Now, to your point, I have no idea how the cut of these diamonds compares to those on rarecarat. This is harder than I thought!
  16. davidelevi

    Deciding on a Diamond - Need help!

    Prices seem fair. Bear in mind that synthetic/lab diamonds have a very different pricing structure (and that IGI and GIA colour and clarity grades aren't exactly interchangeable) The key is that you (and we) know nothing about the cut quality, but it's going to be the one attribute that most impacts the looks. There is nothing in the table you posted (and precious little in a complete GIA report) that tells you whether an oval is well cut. You need to see the diamond; ideally in person and comparing different stones next to each other, but at the very least in good quality photos and videos. I wouldn't say "you shouldn't" - the issue with clarity grading is that it is only roughly correlated with actual visibility of the inclusion to the naked eye and its aesthetic impact. I have seen VS2 that have an annoying black spot right under the table, and once you have seen it you will keep seeing it... and I have seen I1 (the grade below SI2) which seem perfectly eye-clean in most circumstances. So, the lower the clarity the more cautious you have to be, and the more the price is going to be influenced by the visibility of the inclusion... but that doesn't mean that SI2 or even I1 are 'bad' stones.
  17. Hello! I am in the process of picking out a diamond for an engagement ring. My girlfriend is dead set on an Oval stone and I am now trying to figure out what grade, clarity, etc. stone to buy. I have a family friend who owns a Jewelry store who is trying to help me out. I am looking for some feedback here on if the stones below are: 1. Fairly priced? 2. Good grades based on the 4C's? I was reading some articles that I shouldn't go below SI1 clarity, especially as you start getting a little bit bigger on the stone size. Ideally, I'd like to spend about $10K max. Should I consider going to an SI1 clarity and moving the color from G to H? The one thing I haven't learned from the Jeweler is what the "cuts" are. I'm going in tomorrow to discuss further, but these are the stats they gave me so far. I also did a comparison on BlueNile as a gut check. I greatly appreciate your thoughts and help!
  18. davidelevi

    Knot in Diamond

    Good advice... if you can see the stone! Not always the case, even disregarding COVID-caused issues. This I don't particularly agree with. If the stone were cut using very old-fashioned proportions, it would not receive a cut grade of 'Excellent' or even be classified as a "round brilliant". If a stone's surface is marred by wear, it would not be graded 'Excellent' for polish (and/or it would have a lot more external characteristics such as chips).
  19. BenLorken

    Knot in Diamond

    Apart from the report, look at the diamond itself. The report may not indicate that the stone is cloudy or already very old.
  20. denverappraiser

    are these good prices

    Here's 250 comps, for example. https://www.diamondreview.com/diamonds?sortOrder=price&sortDesc=0&fShape=Rnd&fCaratLo=1.01&fCaratHi=1.04&fColorLo=G&fColorHi=G&fClarityLo=VS2&fClarityHi=VS2&fCutLo=exc&fCutHi=exc&fDepthLo=50.0&fDepthHi=80.0&fTableLo=40.0&fTableHi=80.0&fSymLo=&fSymHi=poor&fPolLo=&fPolHi=poor&fCulLo=&fCulHi=vlarge&fFlrLo=&fFlrHi=vstrong&fPriceLo=0&fPriceHi=1000000&fLabGIA=1&fLabAGS=1
  21. denverappraiser

    are these good prices

    I've never personally done business with them, which means nothing, but they're large and seem to be well regarded. They're one of the advertisers on RareCarat (which doesn't really impress me, by the way). Terms and conditions are good. Lots of positive reviews. They've got a physical store in San Fransisco, which is evidence that they're decently well established. They're a virtual seller, which means they don't own or even have most of what they sell. That comes with some troubles but it's fairly typical in this business. Inventory is a problem for jewelers and relying on a supply chain that starts in India causes trouble. Stones are shared with other stores all over the world so there's a very real possibility that something will get sold somewhere else and they won't even know until they try to buy it. Their reviews are lots of 5* and a few 1*'s with very little in between. This is the reason. It's not actually 'bait and switch' but it feels like it because they don't actually have what they're selling and there's a greater than zero chance that they can't get it. Again, this is typical. You'll see a few complaints about this in the reviews of pretty much any Internet diamond dealer using the virtual inventory system. I think every seller advertising here has the exact same issue. The alternative is dealers who carry things in inventory which means less selection and higher prices. That's why they look attractive in the RareCarat lens. All in all, they look pretty good. In terms of prices, it's pretty easy to check yourself. I'd be willing to bet you already have. Do a search in one of the giant virtual databases, like the one behind the 'Diamond Finder' link at the top of the page, and search for similar stones. You'll usually find dozens of choices from nearly as many vendors. It's easy to see who is price aggressive and who isn't. The big differences are normally in the terms and conditions, not so much the prices.
  22. darrellhatchell

    are these good prices

    1.02 G VS1 YD12500431 $7012 is Yadav a trustworthy supplier of quality Diamonds
  23. Katherchill

    Tiffany&Co. Etoile Diamonds & 18k Gold wedding band

    It looks absolutely incredible. I had a similar bracelet, but I bought it at the Cartier store in Paris. Still, I wouldn't step aside when talking about another bracelet. I don't think my husband will be upset with me. Moreover, he already bought himself a new tuxedo from https://www.gentlemansguru.com/product-category/wedding/groom/ and now it is my turn. Can I ask you for more details about the wedding band? Why do you sell it, and how much did you had it.
  24. satbeachbill

    Can't choose between 2 Stones

    Thanks, That helps me understand it a little better. Bill
  25. davidelevi

    Can't choose between 2 Stones

    It's not that simple, but it's not that complicated either. Depth as such doesn't tell the story, but a stone with a higher crown and a narrower table will probably be more fiery (and probably less bright) than one with a shallower crown and a broader table. It will also tend to be deeper, in as much as the crown height is part of the depth - but "greater depth" alone could mean a steeper pavilion or a thicker girdle as well as a higher crown... neither of which does anything for fire (or brightness, for that matter). This said, the crown angle has to work well with the pavilion angle so that light is reflected back to the observer's eye and not lost through the stone (very shallow pavilion) or at an angle rather than directly back (very steep pavilion), so again a bulky crown by itself is no guarantee of a fiery stone either.
  26. satbeachbill

    Can't choose between 2 Stones

    Davidelevi, In your example of prisms and mirrors, brightness vs fire, is that directly related to the depth of the stone? Or is is not that simple? You said when comparing the 2 stones, the VG would show more fire. It is cut considerably deeper that the EX. Thanks, Bill
  27. Diamond14

    Looking for opinions on this oval I recently bought

    Thank you so much for your advice. That is really helpful and I will definitely do as you suggest. I really appreciate your insights 😊
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