From our previous posts we know the fundamentals

Size = Carats

Quality = Cut (glitter), Color(how white) and Clarity (blemishes)

we also covered how increasing the size or the quality increases the cost

Size↑ + Quality↑ = Cost ↑↑

We also saw that ‘Perfect’ quality diamonds (D color, IF clarity and Excellent Cut) quickly rack up the cost.

Picking the Best Diamond

“For my budget of $X,000. What is the best diamond?”

In today’s blog post we will find that buying ‘perfect’ quality diamonds is often not the best deal or way to spend your budget

We can choose slightly lower quality which still looks fabulous and use the saving to buy a larger carat (size). Read on …

Quality ‘Zones’

We can think about quality in three zones

Zone 1
Perfect under a microscope
Zone 2
Perfect to the human eye
Zone 3
Issues visible to the human eye
Cut D, E, F G, H, I J, K, L
Clarity Flawless, Internally Flawless, Very Very Slight Very Slight Slight and Included
Color Excellent Excellent Very Good, Good & Poor

Now …. it is rare that when your fiancee shows off the ring off people will whip out a microscope!

Spending budget in ‘zone one’ buys quality not visible to the human eye

Instead, you want to drop a few grades on the scale on Clarity and Color and use those savings to buy a bigger diamond.


Returning to the table of options we covered in our first blog post we can see these quality zones in action.

Remember: without a microscope it is hard to tell the difference between zone 1 and 2

Option Size (Carats) Quality Cost
Perfect Quality but Small 0.98 Flawless under microscope $9,481
Great Quality and Medium Size 1.50 Flawless to human eye $9,941
Larger but Poorer Quality 2.01 Visible flaws to the human eye $9,736

We can buy a diamond which is 50% bigger for the same budget and without compromising on quality!

Don’t Compromise on Cut

You may notice that we lowered the Cut. The reason for this is that the Cut of a diamond is visible when you start to lower the quality.

OneTrueRock Recommendations

In OneTrueRock our algorithms are helping you to find the biggest and best quality diamond for your budget.

Spending budget on Color or Clarity that is not visible to the human eye is generally not the best use of money. As a result our algorithms often recommend diamonds in the GHI color range, VVS2-VS2 clarity range and with Excellent Cut.

On the OneTrueRock site search page we help you visualize this.

Efficient Diamonds

Diamonds are a trade-off between size and quality. We take thousands of diamonds and sort them by size and quality.

We then find the diamonds which are the biggest and most beautiful quality. We try to

  • prevent overpaying on quality that is not visible
  • avoid recommending diamonds that start to have visible quality issues