OTD Diamonds is the resale collection of a second-generation diamond dealer and GCI-certified gemologist. Every piece is personally examined before it's offered.
New acquisitions are added as they become available. Each piece is individually evaluated before being offered by OTD.
Straight answers on grading, value, and what actually matters when you're buying or selling.
Cut, Color, Clarity, Carat. Four words every diamond ad leans on. Here's what they actually mean for the stone in front of you, and which one matters most for how it looks on the hand.
Read the Full Article →A grading report looks intimidating until you know which three numbers to check first. Here's the section-by-section breakdown, and the red flags that mean a stone needs a second look.
Read the Full Article →Karat stamp, weight, and the day's spot price get you close. Condition, craftsmanship, and whether a piece is worth more whole than melted can change the number substantially.
Read the Full Article →Same carbon, same crystal structure, same grading scale. The difference isn't what the stone is made of. It's where it came from, and what that means for what it's worth over time.
Read the Full Article →A lab diamond can look identical to a natural one and still be worth a fraction of the price a year later. Here's the supply-side reason, not a sales pitch against them.
Read the Full Article →Gold trades on a transparent global spot market, updated by the minute. A diamond's value depends on the individual stone, its rarity, and the resale market for that specific type of piece.
Read the Full Article →Three numbers, three different jobs. Confusing them is the single most common reason sellers feel shortchanged when it's time to actually sell a piece.
Read the Full Article →Every diamond ad you've ever seen leans on the same four words: Cut, Color, Clarity, Carat. They're a useful shorthand, but on their own they don't tell you which stone actually looks better in person. That's the part that matters when you're spending real money.
Cut is the one buyers underweight the most. It's not the shape of the stone. It's how precisely it was proportioned and polished to handle light. Two diamonds with identical color and clarity grades can look completely different on the hand because one was cut to a much tighter standard. If you only prioritize one C, prioritize this one.
Color is graded on a scale from D (colorless) to Z (noticeably tinted), and the differences at the top of the scale are subtle enough that most people can't see them without a trained eye and a comparison stone. Where color matters more is in larger stones, where any tint becomes easier to spot.
Clarity refers to internal and surface characteristics formed while the stone was growing. Most of these are invisible to the naked eye at normal grades. Grading is done under 10x magnification, not by eye. A stone doesn't need to be flawless to look flawless.
Carat is simply weight, not size. Two stones of the same carat weight can face up differently depending on how they're cut. It's the easiest number to compare and the easiest one to overpay for if the other three are ignored.
A well-cut diamond in the middle of the color and clarity scales will almost always outshine a poorly cut diamond with "better" numbers on paper.
← Back to the JournalA GIA report is dense, but you only need to check a handful of fields to understand what you're looking at. Start with the four numbers already covered in the 4 Cs: cut, color, clarity, and carat weight. They're printed near the top of the report.
Next, check the measurements and proportions. These numbers help explain how the diamond carries its weight and, for round brilliant diamonds, provide useful context alongside the GIA cut grade.
Look at fluorescence. Most stones are rated "None," which is preferred by most buyers, though faint fluorescence rarely affects appearance and can sometimes make a stone appear whiter.
Finally, verify the report number directly through GIA Report Check. Some GIA-graded diamonds also have the report number laser-inscribed on the girdle, which provides an additional way to match the diamond to its report. Laser inscription is included with certain GIA services and optional with others, so the absence of an inscription alone is not a red flag.
What the report won't tell you: how the stone actually looks in person. Grading numbers are a floor for quality, not a substitute for seeing the piece.
← Back to the JournalThe starting point for any gold piece is simple math: karat purity times weight times the day's spot price. A 14k piece is 58.5% pure gold; 18k is 75%. That calculation sets a floor, but it's rarely the full story.
Condition matters more than people expect. A piece with intact prongs, no cracked solder joints, and clean stones is worth evaluating as a wearable piece first, and scrap second.
Craftsmanship and maker can push a piece's value well above melt value. A well-made estate piece, a signed piece from a known house, or handwork that isn't being produced anymore can be worth more intact than broken down.
Stones set in the piece are valued separately from the metal. A gold ring with a genuine diamond or colored stone should never be priced as if it were plain scrap gold. The stone gets pulled and evaluated on its own.
The honest answer: get it looked at by someone who checks all of this before quoting a number, not just a scale and a magnet.
← Back to the JournalA lab grown diamond is not a simulant. Lab grown and natural diamonds have essentially the same chemical composition, crystal structure, and optical and physical properties. They are real diamonds and can be evaluated for the same fundamental quality characteristics buyers consider in natural diamonds.
The difference is origin and timeline. A natural diamond formed over a billion years or more, deep in the earth, and was mined. A lab grown stone is produced in weeks using high-pressure high-temperature or chemical vapor deposition equipment. Both are real diamonds; they simply arrived here differently.
Where it matters most for a buyer is price and trajectory. Lab grown diamonds are priced closer to their production cost, and that cost tends to fall as growing technology scales and more producers enter the market. Natural diamonds come from a finite geological resource and cannot be manufactured on demand, which behaves very differently over time.
Neither is the "wrong" choice. A lab grown stone gets you more size and clarity for the same budget, and that's a legitimate reason to choose one. What it isn't is an investment in the same sense a natural stone can be, and any buyer should walk in knowing that distinction, not learn it later.
← Back to the JournalThis isn't a marketing line against lab grown diamonds. It's a straightforward supply-side reality worth understanding before you buy one expecting it to hold value like a natural stone.
Natural diamonds come from a finite geological resource and cannot be manufactured on demand. Lab grown diamonds have no such ceiling. Production capacity keeps expanding, and every new grower and every efficiency gain pushes wholesale prices down further. What cost a certain amount to produce last year costs less this year, and that keeps happening.
Retail prices on lab grown stones have been falling accordingly as a result. A diamond bought at full retail price today is, by the time you'd go to resell it, competing against newer stock produced more cheaply. Dealers price accordingly, because they have to.
None of this makes a lab grown diamond a bad purchase for someone who wants the look at a lower price and isn't thinking about resale. It does mean the two categories shouldn't be evaluated by the same yardstick, and a buyer treating a lab grown stone as a store of value is operating on a false assumption.
← Back to the JournalGold and diamonds get lumped together as "precious materials," but they're priced in fundamentally different ways, and understanding that difference matters whether you're buying or selling.
Gold trades on a transparent global spot market. An ounce of gold is worth the same wherever you check, updated continuously, because gold is a fungible commodity: one ounce is interchangeable with any other ounce of the same purity. That's why the live price shown at the top of this page is meaningful as a real-time reference.
A diamond doesn't work that way. There is no single "diamond price" the way there's a gold price, because no two diamonds are identical. Value depends on the specific stone's cut, color, clarity, and carat weight, plus factors a spot price can't capture: rarity at that particular combination of characteristics, current demand for that shape and size, and the depth of the resale market for that category of stone.
That's also why diamond values can move differently across categories at the same time. A rare, high-quality natural stone and a common mid-market stone don't necessarily move together, because they're really two different markets with different buyers and different supply dynamics.
The practical takeaway: gold's price is a number you can look up. A diamond's value takes an actual evaluation of that stone, not a lookup.
← Back to the JournalThis is the single most common source of frustration when someone goes to sell a piece, and it usually comes down to comparing three numbers that were never meant to match.
Insurance appraisal value is a retail replacement figure. It answers "what would it cost to walk into a jewelry store and buy this exact piece new, today." It's intentionally on the high end, because that's what it would actually cost you to replace it if it were lost or stolen.
Appraisal for other purposes, like estate or resale documentation, can land closer to fair market value, which is already lower than the insurance figure.
What a buyer will actually pay is a wholesale number. A dealer buying your piece has to resell it, cover overhead, and make a margin, so the offer reflects what the piece is worth to them as inventory, not what it would cost a stranger to replace it at full retail.
The gap between those numbers isn't anyone padding a figure or lowballing an offer. It's three different questions with three different honest answers. Understanding which number applies to which situation is the difference between a seller feeling informed and a seller feeling shortchanged.
← Back to the JournalO.T.D Diamonds acquires pieces individually and evaluates each one personally before it's offered for sale. There's no dropshipping and no unseen inventory. What's listed is what's in hand.
Buyers deal directly with the person who evaluated the piece, not a call center.
Second-generation diamond dealer with more than 20 years in the trade. GCI-certified gemologist and longtime member of the Israel Diamond Exchange, now based in Houston.
Every piece offered by OTD is evaluated personally. When you contact OTD about an item, you're speaking directly with the person who examined it.
Pieces may originate from private owners or trade opportunities and are evaluated before being selected for OTD inventory. Where an item's history is genuinely known, it's noted individually.
Personally evaluated and documented for insurance, resale, or peace of mind. Starting at $50 for a standard item, scaling with complexity and quantity of pieces.
Reference the lot number and speak directly with Idan about condition, specifications, certification, payment, shipping, or viewing the piece.
O.T.D Diamonds · 6222 Richmond Ave, Suite 372, Houston, TX 77057 · Visits by appointment