Hot springs water is not just warm water. As it travels underground, it picks up minerals from the rock around it, and those minerals give each spring its own chemistry, smell, and feel on the skin.

This guide explains how minerals end up in hot springs water, which ones are most common, and how to read a mineral analysis. It then walks through the 13 minerals in the Mother Spring at The Springs Resort in Pagosa Springs, Colorado, the Guinness-verified world’s deepest geothermal hot spring.

How Minerals Get Into Hot Springs Water

Most hot springs start as rain and snowmelt. The water seeps down through cracks in the earth, where it is heated by surrounding rock. Hot water dissolves minerals more easily than cold water, so on its way back to the surface it carries a load of dissolved elements from the rock it passed through.

That is why no two springs are identical. Geology, depth, and how long the water stays underground all shape what comes out at the surface.

Common Minerals Found in Hot Springs

Every spring is different, but a handful of minerals show up again and again:

Sulfate and sulfur compounds: Behind the familiar mineral smell at many springs

Sodium and chloride: The components of salt, common in many geothermal waters

Calcium and magnesium: Often responsible for water described as “hard”

Silica: Dissolved from volcanic and granite rock, often linked to a soft feel on the skin

Potassium, lithium and boron: Usually present in smaller amounts

Trace elements: Iron, zinc, manganese, and others, measured in very small concentrations

How to Read a Hot Springs Mineral Analysis

Mineral content is usually listed in milligrams per liter (mg/L), the weight of each mineral dissolved in a liter of water. A few things help when comparing springs:

Higher is not automatically better. Concentration describes the water; it is not a quality score.

The count depends on the test. One spring may list nine minerals and another 13 because of what each analysis measured.

The source matters as much as the list. Natural geothermal water rising from the earth is different from tap water with minerals added or tap water that is simply heated.

Look for published numbers. Properties that share a full analysis make it easier to understand what you are soaking in.

The 13 Minerals in the Mother Spring

The Mother Spring feeds every pool at The Springs Resort. Guinness World Records verified it as the world’s deepest geothermal hot spring at 1,002+ feet, and the water reaches the surface at about 144°F. The resort publishes the following mineral analysis, listed here from highest to lowest concentration.

What Makes the Mother Spring’s Profile Stand Out

Sulfate and sodium make up most of the Mother Spring’s mineral content, which places it among sulfate- and sodium-rich geothermal waters. Silica, potassium, and magnesium are present in meaningful amounts, and the rest of the list appears in trace concentrations.

It’s important to note that the water comes straight from a natural geothermal source. Many pools marketed as mineral pools use municipal water with minerals added, or simply heated tap water. At The Springs Resort, all 50+ pools are fed by the Mother Spring itself.