Geothermal water and your skin: the silica story

Step out of an Icelandic lagoon and one of the first things you notice is how your skin feels: smooth, calm and faintly polished, as if the water gave something back. That feeling is no accident. Iceland's geothermal water rises through young volcanic rock and carries minerals with it, and silica is the quiet star of the story. Here is what is happening in the water, and how to soak so your skin loves every minute.

Where the minerals come from

Rain and meltwater seep deep underground, where the earth heats them and dissolves traces of the surrounding rock. By the time that water surfaces it can hold silica, sulphur and other minerals in solution. Silica is simply dissolved silicate, the same family of compounds that makes up much of Iceland's bedrock. As the hot water cools and meets the air, some of that silica turns milky and settles as the soft pale mud you see gathered at the edges of certain lagoons. That gentle haze in the water is the mineral made visible.

What silica does for the skin

Silica is prized in skincare for a reason. In a soak it leaves a light, velvety film that many people describe as a natural softening, and the fine pale mud is loved as a simple, soothing mask. At the Blue Lagoon the whole spa grew up around exactly this: the milky, silica rich water and its white mud have been studied and bottled for years, and the lagoon invites you to scoop a handful, smooth it on and rinse it away before you leave. You come out feeling clean and refreshed rather than dried out, which is the opposite of what a long hot bath at home usually does.

Every lagoon has its own character

The mineral makeup changes from place to place, and so does the feeling on your skin. The wide, mineral rich Earth Lagoon (formerly Mývatn Nature Baths) in the north draws on alkaline geothermal water and has its own soft, faintly sulphurous character, with the lagoon often almost to yourself on a quiet evening. Down south, the calm terraces of Sky Lagoon fold a body scrub into a seven step ritual that leaves skin glowing. Tasting the difference between waters is part of the pleasure of soaking your way around Iceland.

The water does the gentle work; your skin simply has to stay in it long enough to notice.

A friendly word about sulphur and silver

Some Icelandic water carries a little sulphur, which gives it a faint earthy smell and is harmless on skin. Silver jewellery is the one thing worth minding, since sulphur can dull it, so it is wise to leave rings and chains in your locker before a sulphur rich soak. Hair is the other point to plan for. Mineral water can leave longer hair feeling dry, so most lagoons offer free conditioner and suggest you coat your hair and tie it up out of the water, a small habit that keeps it soft.

How to soak so your skin thrives

• Shower without swimsuit first, as Icelandic custom asks, so your skin starts clean and the water stays clear for everyone.
• Condition and tie up long hair, and use the conditioner the lagoon provides before you get in.
• Leave silver in the locker if the water is sulphur rich, to keep it bright.
• Try the mud if it is offered, smoothing a thin layer on, letting it rest and rinsing it off before you leave.
• Drink water and cool down between soaks, since hot bathing is gently dehydrating for skin and body alike.
• Moisturise afterwards to lock in that fresh, soft feeling once you have dried off.

Want to go further? See the full picture in our guide to the health benefits of geothermal bathing, plan a pampering day with the best spas in Iceland, or learn the hot then cold then rest rhythm in Nordic spa rituals and contrast bathing.