Tanzanite Sleep Mattress, Bonnell Spring, Memory Foam & Cooling Gel Comfort

If you want the pressure-relieving feel of memory foam without paying pocket-spring prices, the Tanzanite Sleep Mattress is built for that. It combines a traditional Bonnell open coil spring base with two comfort layers, 50mm memory foam and a 25mm GelFlex topper, giving you genuine body contouring, motion absorption, and cooler surface temperature in a mattress that starts at £159.99.

It’s a medium-feel mattress. Not too firm, not too soft. The kind of feel that works for most sleepers and most sleeping positions, whether you’re on your back, on your side, or switching between the two throughout the night.

What’s inside the Tanzanite Sleep Mattress

• 175mm Bonnell Spring Unit, the responsive, interconnected spring core that gives the mattress its structure and durability. Bonnell springs have been the reliable workhorse of the mattress industry for decades, supportive, breathable and proven.
• 50mm Memory Foam Layer, sits above the springs and moulds to the contours of your body, distributing weight evenly and reducing pressure on hips and shoulders.
• 25mm GelFlex Layer, the top comfort layer. Adds softness and actively draws heat away from the sleep surface so you’re not sleeping hot.
• Hypoallergenic materials throughout, suitable for allergy-sensitive sleepers and households.
• Stretch-knitted, zipped cover; removable for easy cleaning; holds its shape wash after wash.
• Mattress handles make repositioning straightforward, especially at this size.
• Turnable design: rotate every 3 months, even out to wear and extend the mattress’s life significantly.

Made in the UK.

Who is the Tanzanite Sleep Mattress for?

It’s the right choice if you want memory foam comfort without a fully foam mattress. The Bonnell spring base keeps airflow moving through the mattress, which all-foam options can’t match. It works particularly well for couples sharing a bed when one partner runs warmer, or for guest rooms and children’s rooms where you want a quality mattress without overspending. It pairs with any Style Beds upholstered bed frame, ottoman divan or TV bed base.

Style Beds, why buy with us

• Free UK delivery, 3 to 5 working days, nationwide
• 30-night risk-free trial, if the Tanzanite isn’t right for you within 30 nights, we’ll collect it and refund you in full, no questions asked
• 3-year warranty, full cover against any manufacturing defect from the date of delivery

Frequently Asked Questions (FAQ’s)

Is the Tanzanite a pocket spring or an open coil mattress?

It’s an open coil (Bonnell) spring mattress. Bonnell springs are interconnected across the mattress; they respond as a unit, which gives a buoyant, traditional spring feel. Pocket springs are individually wrapped and respond independently, which tends to reduce motion transfer. The Tanzanite’s memory foam layer compensates for this by absorbing movement before it reaches your partner.

Can I use the Tanzanite Sleep Mattress with an ottoman bed frame?

Yes, it’s compatible with all Style Beds ottoman divans and standard divan bases, as well as slatted and solid platform bed frames. The removable zipped cover makes it easy to handle when lifting the ottoman base.

Is it one-sided or two-sided?

The Tanzanite is turnable. We recommend rotating it 180° every 3 months, even out to wear and prolong its lifespan.

Does it sleep hot?

The GelFlex top layer is specifically designed to regulate surface temperature, and the Bonnell spring core allows airflow throughout the mattress. It performs noticeably better at regulating temperature than all-foam alternatives at a similar price.

What is the depth of the Tanzanite mattress?

Approximately 25cm total depth, deep enough to work with most fitted sheets and compatible with standard divan and platform bases.

How long does delivery take?

3 to 5 working days across the UK. All Tanzanite Sleep Mattress orders include free delivery, no minimum spend, and no surcharge for larger sizes.