Mineral Water Guide
Why mineral waters differ
Every water tells the story of its source - and no two sources are the same.
Every natural mineral water originates from a specific geological source. As water travels underground through layers of rock and soil, it dissolves minerals from the surrounding environment - and the result is a unique mineral composition that cannot be replicated.
What Shapes Mineral Composition
Four geological factors determine what ends up in your water:
Rock type
Limestone, volcanic, granite - each rock dissolves different minerals into the water
Aquifer depth
Deeper sources typically have longer contact with minerals, resulting in higher mineralization
Flow path
The underground route water takes determines which minerals it encounters along the way
Contact time
The longer water remains in contact with rock, the more minerals it absorbs
Why This Matters for You
Because geological formations vary significantly, two springs located only a few kilometers apart can produce waters with very different mineral content.
This natural variation is what makes mineral water uniquely selectable - you can compare real compositions and choose the water that fits your preferences, rather than settling for whatever happens to be available.
Four sources, four geological stories
The table compares four waters from four countries using mineral concentrations from the h2oMatch database. Each source sits in different rock, and the comparison shows how strongly geology and groundwater conditions shape what ends up in the bottle.
| Water | Calcium (Ca) | Magnesium (Mg) | Sodium (Na) | Bicarbonate (HCO₃) |
|---|---|---|---|---|
| Ferrarelle (Italy) | 400 | 23 | 50 | 1,500 |
| Volvic (France) | 13 | 9 | 12 | 80 |
| VOSS Still (Norway) | 2.7 | 0.6 | 3 | 20 |
| FIJI Natural Artesian Water (Fiji) | 18 | 14 | 16 | 125 |
Values in mg/L from the h2oMatch database (producer label data).
VOSS Still comes from a source in Iveland, southern Norway, where groundwater is held in old, hard crystalline bedrock that dissolves very slowly; little calcium, magnesium or bicarbonate is picked up, so it is the lightest of the four. Volvic (Auvergne, France) filters slowly through layers of volcanic rock; it stays light, but those rocks release more magnesium, sodium and silica than VOSS's bedrock.
FIJI is an artesian water: it is drawn from a confined aquifer in volcanic rock on Viti Levu, where natural pressure raises the groundwater towards the surface. Longer contact with volcanic rock gives it more calcium, magnesium and bicarbonate than Volvic. FIJI is sold as natural artesian water; it is not presented here as an EU-recognized natural mineral water. Ferrarelle (Riardo, Campania, Italy) rises in a volcanic area rich in natural carbon dioxide. Water carrying CO2 becomes slightly acidic and dissolves more rock, which helps explain why its bicarbonate and calcium are far higher than in the other three.
The lesson is practical: brand image says little about composition. Depth, rock type, contact time and dissolved gases matter more than a country or a famous name, so the label, not the origin story, is what to compare. The table shows individual mineral concentrations only, not fixed residue or total dissolved solids.
Key takeaway
The source determines the composition, not the brand name. That is why reading the label - and comparing mineral profiles - is the most reliable way to understand what you are actually drinking.
FAQ
Why do mineral waters have different compositions?
Each mineral water comes from a unique geological source. As water travels underground through different rock layers, it absorbs different minerals in different concentrations - making every source unique.
Can two nearby springs produce different water?
Yes. Two springs only a few kilometers apart can have very different mineral profiles because they flow through different rock formations and at different depths.
Does the brand determine water quality?
No. The geological source determines mineral composition, not the brand. Reading the label is the most reliable way to understand what is in your water.