Diamond Mattress Review

Diamond Mattress Review - Bed by itself

Great for:

  • All sleep positions
  • Hot Sleepers
  • Couples
  • Seniors

Type – Hybrid

Firmness – Plush, Medium, & Firm

Sleep Trial – 120-night

Warranty – Forever

Shipping – FREE

In This Article

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Brand Quickview

Relatively new to the bed-in-a-box scene, Diamond Mattress is not, however, new to the mattress and bedding industry. Family-run and operated, Diamond Mattress has over 80 years of experience manufacturing mattresses and sleep wellness products! 

Offering an extensive selection of beds online, we look at one of their most popular models. In our Diamond Mattress review, we go inside the Diamond Transformation Hybrid to discuss construction, firmness and feel, best sleep positions, mattress performance, purchase details, and more to help you decide if this mattress is the right fit for you!

Diamond Mattress YouTube Review

Diamond Mattress Construction

The Diamond Transformation Hybrid boasts a 14” mattress profile and features a combination of foam and coils. Made in the USA, Diamond makes their coils from recycled steel. Additionally, Diamond mattresses are made with certiPUR-US certified foams for an eco-friendly approach to design.

Cover – The Transformation Hybrid mattress cover is a stretchy knit design featuring 2” of quilting for a comfortable, luxurious surface feel. It is made with advanced phase-changing material (PCM), which is cool to the touch and actively helps regulate temperature.

2” Diamond Hyper-Conductive Sparkle Foam – This memory foam layer provides nice contouring and pressure-relief. It includes graphene and conductive flakes, which promote heat dissipation and ensure a comfortable sleep temperature throughout the night.

Micro-Coil Comfort Layer – Over 1,000 wrapped micro-coils work with the memory foam above to relieve pressure. The coil design further enhances airflow and breathability.

2” HD Comfort Layers – This hyper-conductive foam layer acts as a transition between the comfort layers above and the firm, supportive coils below. Sleepers will benefit from the additional contouring and pressure relief which prevents sleepers from sinking directly into the support layer.

Patented Zone Support System – Zoned coils provide targeted support where you need it most without compromising comfort. The coil system includes individually wrapped coils for better motion isolation and enhanced breathability and airflow.

Mattress Handles – The bed comes with mattress handles for easier maneuverability. 

Diamond Mattress Close Up of the Bed Cover

Firmness and Feel

The Diamond Transformation Hybrid is available in 3 firmness options: plush, medium, and firm. We reviewed the medium firmness option, which is considered their bestseller. Overall, we rated the mattress a 5 on the firmness scale.

The top layers of the mattress feel quite plush and contouring, providing immediate comfort from the moment we climbed into bed. Unlike the denser feel of all-foam mattresses, the Transformation Hybrid has an airy, almost buoyant feel, like you’re floating in the clouds. 

Though described as having a medium feel on Diamond’s website, we think it has a medium-soft feel which it accomplishes without losing support. Equally so, we felt well supported through the lumbar. As a result, this is one of the few mattresses we’ve tested that we found suitable for all sleep positions. Let’s take a look!

Related: What Mattress Type Is Best For Your Body?

Testing the firmness of the Diamond Mattress

Side Sleepers

Side sleeping leaves sleepers vulnerable to the build-up of pressure through their hips and shoulders. If you suffer from sleep-related shoulder or hip pain, this bed could be an excellent choice. 

The quilted top layer provides instant contouring and sinkage, melting away stubborn pressure points. The zoned coil system kept us lifted through the mid-section promoting proper alignment.

Lightweight side sleepers (Under 130 lbs.)  and individuals who prefer a very soft mattress feel may want to consider the plush version of this mattress.

Back Sleepers

Back sleepers are best served by a balance of pressure relief and support. This sleep position requires gentle contouring through the lower back and the hips. Too much contouring can pull the back out of alignment, causing aches and pain.

Back sleepers of all weights should be quite pleased with the Transformation Hybrid. However, heavier individuals may find the firm model is a better fit.

Man demonstrates back sleeping on the Diamond Mattress

Stomach Sleepers

Surprisingly, I think this could be a good option for most stomach sleepers as well. While generally firmer mattresses are recommended for stomach sleepers, the zoned coil system offers nice support through the midsection. When sleeping on my stomach, my hips remained lifted, and I did not experience any pressure or strain on the base of my spine. The medium could be a good option for stomach sleepers who also favor sleeping on their sides (combination sleeping).

Strict stomach sleepers and heavier individuals (230+ lbs) may want to consider the firm version of this mattress.

Related: The Best Mattress for Heavy People

Diamond Transformation Hybrid Mattress Performance


Hybrid mattresses are consistently one of the best choices for hot sleepers. By design, hybrid mattresses promote airflow and breathability, which helps avoid trapped heat, promoting a cooler sleeping experience.

The Diamond Transformation Hybrid Mattress features advanced phase-change materials and graphene, both of which aid in heat dissipation, allowing sleepers to get the rest they need. Overall, we think this is an excellent choice for hot sleepers.

Related: What is the Ideal Sleep Temperature?

Motion Isolation

We think the Diamond Transformation Hybrid did a pretty good job isolating motion. Typically, hybrid mattresses tend to struggle a bit with motion transfer. Due to the nature of the coil system, sleepers may find hybrids demonstrate more motion transfer than all-foam alternatives. Additionally, coil mattresses have a greater tendency to be noisier. 

Pleasantly, this was not the case with the Diamond Transformation Hybrid. The plush memory foam top layers did a great job of isolating motion leaving us undisturbed by our partner throughout the night. Moving around on the bed, we experienced very little, if any, noise.

Edge Support

Diamond’s Transformation Hybrid Mattress features a foam-encased comfort edge. This encasement surrounds the coil system providing reinforced edge support. As a result, sleepers can enjoy a larger sleep surface with edge-to-edge comfort throughout the night.

Good edge support allows sleepers to enter and exit the bed easier, especially important for seniors and individuals with injuries or disabilities who may otherwise need assistance.

Man Sitting on Edge of Diamond Bed

Ease of Movement

Ease of movement is a particularly important metric for combination sleepers. Mattresses made with memory foam can leave sleepers feeling bogged down. However, the thick foam comfort layers of the Diamond Transformation hybrid are quick to respond, offering above-average ease of movement.

Diamond Mattress Purchase Details

Risk-Free Sleep Trial

Diamond offers a 120-night risk-free sleep trial starting when your mattress is delivered to your doorstep. Adjusting to a new mattress can take time, and mattress break-in periods can vary. 

Should you find your new mattress isn’t to your satisfaction, Diamond will work with you to schedule a pick-up (at no cost to you) and either exchange your mattress for another one on their site or issue a refund. All returned mattresses are recycled or donated to charity.


Shipping is free within the contiguous US. Shipping to Hawaii and Alaska is available for a fee.


Diamond mattresses come with a Forever Warranty, guaranteeing the construction, materials, quality, and durability of your Diamond mattress for the original purchaser.

Diamond Mattress Bed Sizes, Prices, and Financing

The Transformation Hybrid ranges in price from $2,199 to $3,499, as seen in the chart below. The prices shown do not reflect eligible discounts. For current mattress deals and discounts, please see our coupon below.

Financing is available through Affirm with payments as low as $119/month (subject to approval).

Mattress Price

Bed Dimensions

Mattress Weight



39 x 75 x 14

53 LBS

Twin XL


39 x 80 x 14

58 LBS



54 x 75 x 14

67 LBS



60 x 80 x 14

80 LBS

Eastern King


76 x 80 x 14

100 LBS

Cal. King


72 x 84 x 14

100 LBS


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