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Lab Grown Diamonds: How Carat Size Affects Price and Appearance

When shoppers begin exploring Lab Grown Diamonds, one of the first questions they ask is about carat size, how it influences both the appearance and the price of the diamond.

It’s a valid concern. For years, we’ve been conditioned to believe that a higher carat means a more valuable diamond. The logic seems simple: the bigger the diamond, the better, right?

Not necessarily. And especially not when it comes to Lab Grown Diamonds.

Unlike Mined Diamonds, Lab Grown Diamonds offer better pricing across carat weights, making larger stones more accessible without compromising on quality. But carat isn't everything. Two diamonds of the same carat can look and cost very differently based on cut, quality, clarity, and overall brilliance.

So while carat size does matter, it's just one part of the equation. In the world of Lab Grown Diamonds, it's about finding the perfect balance between size, sparkle, and what feels right for you, not just chasing numbers.

First Things First: What Is a Carat?

Diamond with carat and weight information on a gray background

It’s easy to mistake “carat” as a measure of size, but technically, it refers to weight. One carat equals 200 milligrams. So, two diamonds can both weigh one carat, but if one is cut shallow and the other deep, they’ll look pretty different in size when set into jewellery.

This is where things get interesting: not all one-carat diamonds appear the same, and that applies whether they’re Mined or Lab Grown.

How Carat Size Affects Appearance

Three diamonds of different cuts and weights on a white background

As carat weight increases, the diamond generally looks larger. But the jump in size isn’t always as dramatic as the jump in weight. For example, a 1.5-carat diamond might not look 50% larger than a 1-carat diamond, it might just appear around 10-15% wider across the top.

The way a diamond is cut also changes how large it looks. A poorly cut 1.2-carat stone may appear smaller than a well-cut 1-carat stone that reflects more light and has a larger surface diameter.

So while carat does affect appearance, it’s not the only factor. Cut, depth, and shape all influence how much presence the diamond actually has.

Why Grown Diamonds Make Bigger More Accessible

Here’s where Lab Grown Diamonds shift the equation: they let you explore higher carat weights without the steep price jump you’d face with mined stones.

Traditionally, Mined Diamonds increase in price exponentially as carat weight goes up. That’s due to scarcity, larger diamonds are rarer in nature. But in a Lab, growing a 2-carat diamond takes more time and energy, but it’s still possible, and not nearly as rare.

That means you can often buy a 2-carat Lab Grown Diamond for a similar price to a 1-carat Mined Diamond, depending on clarity and cut. For anyone who’s always dreamed of a big center stone, this changes things.

Carat vs. Finger Size: What Actually Looks Good?

Gold ring with a diamond on a hand against a beige background

There’s a funny truth that rarely gets talked about in diamond shopping: what looks “big” is relative.

A 2.0-carat diamond might seem huge on someone with slender fingers, while the same stone might feel more subtle on a wider hand. That’s not a flaw, it’s just how proportion works.

Some people want a diamond that makes a statement. Others want something they can wear every day without it feeling oversized. There’s no right or wrong here, it really comes down to what feels balanced to you.

Does Higher Carat Always Mean Better?

Not necessarily. A higher carat doesn’t mean a better diamond.

Let’s say you’re looking at two stones:

  • One is 1.8 carats but has visible inclusions and a dull cut.
  • The other is 1.2 carats, beautifully cut and near-flawless.

The second one will probably sparkle more, look cleaner, and even appear larger to the eye, despite being lighter on paper. It’s a good reminder that cut and clarity matter just as much as carat, sometimes more.Lab Grown Diamonds make it easier to balance all three: size, sparkle, and quality. 

Price Brackets and “Magic Numbers”

Diagram of diamond prices at key carat weights with visual representation of diamonds and price increase indicators.

In diamond pricing, certain carat weights, often referred to as “magic numbers” by jewellers, mark key price thresholds where costs rise significantly.

  • 0.5 carats
  • 1.0 carats
  • 1.5, 2.0, 3.0, and so on

Sometimes, a 0.9-carat stone will cost significantly less than a 1-carat stone, even if the size difference is barely visible. The same goes for 1.8 vs. 2.0 carats.

With Lab Grown Diamonds, you can be a bit more flexible around these markers. You might decide to go just under one of those “magic” weights to save money without compromising on visual size. Or, if budget allows, you might go above them, something that’s often out of reach with mined stones.

So, What Should You Pick?

Rose gold ring with a diamond on a beige background

If you’re torn between carat sizes, here are a few questions to think about:

  • Do you want something bold and eye-catching, or subtle and classic?
  • Will you wear the piece daily, or just on special occasions?
  • Are you prioritizing size, or do you care more about sparkle and clarity?
  • What kind of setting will it be in? (A halo can make a smaller diamond appear bigger.)

Carat size is part of the story—but only part. The right diamond is the one that fits your life, your style, and your values.

At Lucira, It’s Not Just About Size

We don’t believe bigger always means better. What matters is the balance between beauty, ethics, and cost. That’s why we offer a wide range of Lab Grown Diamonds in all shapes and sizes, carefully graded, thoughtfully sourced, and honestly priced.

Whether you're after a classic solitaire or something a bit more unexpected, we’ll help you find a stone that feels like yours, not just something that fits a number on a scale.

Conclusion

Carat size affects both the price and the presence of a diamond. But in the world of Lab Grown Stones, you get more flexibility, more room to explore, and a much better deal.

So instead of chasing size for its own sake, think about what feels right on your hand, what fits your story, and what reflects your values.

That’s what really lasts.

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