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Images: Diamond Mattress. Shown size and configuration may vary.

Diamond Mattress

Dreamstage

Name: Diamond Mattress Dreamstage
Brand: Diamond Mattress

Best for: Half-Cal-King size

A copper-foam hybrid in Plush, Medium or Firm, with or without a Euro top, and a rare 36″ × 84″ Cal Twin XL.

Good to know: The Cal Twin XL costs more than the Queen or King, and returns cost $99.

Type: Hybrid
Height: 14″ or 15″
Sizes: 7 ready-made
Certified: CertiPUR-US, Greenguard Gold

Pick it if

You sleep hot
You share the bed

Skip it if

You need firm edges

From independent reviewers’ findings, credited below.

Your size

36 × 84 in · 14″ or 15″ tall

Where to get it

diamondmattress.comQueen $1,699 (sale price) · checked Oct 17 See price

Returns: 120 nights from delivery; one return or exchange; $99 fee deducted from refund Details

We may earn a commission if you buy. Check the price for your exact size and height on the seller’s site.

The short version

Worth a look if

Half-Cal-King size

Good

A copper-foam hybrid in Plush, Medium or Firm, with or without a Euro top, and a rare 36″ × 84″ Cal Twin XL.
4 firmness choices: Plush, Medium, Firm, Builds: Hybrid or Lux Quilted Hybrid
Trial: 120 nights from delivery; one return or exchange; $99 fee deducted from refund
Height: 14″ or 15″

Think about

The Cal Twin XL costs more than the Queen or King, and returns cost $99.
No owner reviews we could verify yet

Based on the maker’s published specs and terms, and the owner reviews linked below. We haven’t slept on it. Something wrong? Tell us.

What owners say

No owner reviews we can verify yet A small set of real reviews, each linked to its source. Not a star rating.

No owner feedback we can use yet.

What people liked

No supported praise summary in the sample.

What to weigh up

No substantive concern verified in this small sample. This is a gap in the evidence, not proof of no drawbacks.

What independent reviewers found

NapLab (Jul 2026): Testers found very deep but balanced sinkage, strong shoulder and back pressure relief, little motion transfer and a cool-feeling cover, but the unreinforced edge felt soft when sitting. Tested the Medium Firm hybrid version (about 14.5″); soft, firm and all-foam versions weren't tested. Page discloses affiliate commissions. Read it ↗

Their testing, in our words. We haven’t tested these mattresses ourselves, and we don’t repeat their scores.

Sources & sample limits

No usable owner sources. Sample: 0 owner reports.

Owner comments gathered from Reddit via RedditRecs were removed: RedditRecs and Reddit ask automated tools not to collect their content.

Research checked October 14, 2026. These are sourced observations, not our own product tests or a star rating.

Every size it comes in

Bunk (36 × 84)36 × 84 in14″ or 15″Twin38 × 75 in14″ or 15″Twin XL38 × 80 in14″ or 15″Full · 54-inch54 × 75 in14″ or 15″Queen60 × 80 in14″ or 15″King76 × 80 in14″ or 15″California king72 × 84 in14″ or 15″

Taken from the maker’s size options, in the inches it publishes. Tap a size to compare every mattress made in it.

Price for every size

From the maker’s site on Oct 24, 2026. Prices change often, so check before you buy.

Size	Inches	Price
Twin	38 × 75	$1,349 sale	See it
Twin XL	38 × 80	$1,449 sale	See it
Full	54 × 75	$1,599 sale	See it
Queen	60 × 80	$1,699 sale	See it
Cal King	72 × 84	$2,099 sale	See it
King	76 × 80	$2,099 sale	See it

How it compares

Beside the most similar mattresses from other brands.

	DreamstageDiamond Mattress	Elite HybridBear	Elite Ultra HybridBear	Pro HybridBear
Type	Hybrid	Hybrid	Hybrid	Hybrid
Queen price	$1,699	$1,599	$2,129	$1,299
Height	14″ or 15″	14″	13.5″	13″
Trial	120 nights	365 nights	365 nights	365 nights
Odd sizes	1	None	None	None
Expert reviews	1	3	2	4

What’s inside

1CoolTouch Ultra Cool cover (Lux Quilted Hybrid: quilted foam Euro top)
2Copper-infused memory foam
3CertiPUR-US comfort layer
4Individually wrapped coils with Dynamic Edge reinforced perimeter

Feel: Plush, Medium, Firm, Builds: Hybrid or Lux Quilted Hybrid
Height: 14″ or 15″
Custom sizes: Not offered for this model

Complete the bed

Odd sizes need everything else in the same inches. Here’s what we have for this mattress’s odd sizes.

Bunk (36 × 84) · 36 × 84

Returns and ordering

Trial and returns

120 nights from delivery; one return or exchange; $99 fee deducted from refund

Before you order

Measure inside the frame, not the old mattress
Check clearance above for the height you pick
Make sure your base supports it
Buy sheets in the same exact size

Questions

What is it made of?

Copper line: a CoolTouch Ultra Cool cover over copper-infused memory foam, a CertiPUR-US comfort layer and individually wrapped coils with a Dynamic Edge coil perimeter. The Lux Quilted Hybrid adds a quilted foam Euro top. The build descriptions on the same page also mention graphene-infused memory foam.

How firm is it?

Plush, Medium, Firm, Builds: Hybrid or Lux Quilted Hybrid That’s the maker’s description; we haven’t measured it.

Which sizes and heights can I get?

7 sizes, 14″ or 15″. See every size. Confirm your exact size and height with the seller.

Are the reviews about this exact mattress?

No owner reviews we can verify yet. Owner comments gathered from Reddit via RedditRecs were removed: RedditRecs and Reddit ask automated tools not to collect their content.

Where did this information come from?

Checked 2026-10-17. Specs and terms can change.