Manganese comes from the Earth’s crust, where it ranks as the 10th most abundant element and the second most common heavy metal after iron. Crustal rocks contain about 0.1% manganese on average, and near the surface it readily oxidizes into more than 30 different mineral forms. From there, it enters human life through two main paths: mining operations that extract it for industrial use, and the soil where plants absorb it and pass it into the food supply.
Where Manganese Exists in Nature
Manganese oxides are the dominant mineral group in the upper crust and the primary source of industrial manganese. The most historically significant is pyrolusite, a form of manganese dioxide that humans have used for thousands of years, first as a pigment and later to remove the green tint that iron impurities give to glass. In soils, the most common manganese minerals are lithiophorite, hollandite, and birnessite.
Manganese also accumulates on the deep ocean floor. Polymetallic nodules, potato-sized lumps rich in manganese and other metals, sit on the sediment of abyssal plains at depths of 3,500 to 6,000 meters. The largest known deposit is the Clarion-Clipperton Zone in the central Pacific Ocean, which holds a conservatively estimated 21.1 billion dry tons of these nodules. No commercial-scale mining of ocean nodules is currently underway, but they represent an enormous untapped reserve.
Top Mining Countries
Global manganese mine production reached roughly 19.9 million metric tonnes in 2023. South Africa leads the world, renowned for its high-grade ore deposits. Gabon is the second-largest producer, contributing about 4.6 million metric tonnes annually. Australia, China, and India round out the top tier of producing nations. About 90% of all mined manganese goes directly into steel production, where it strengthens the metal and removes sulfur and oxygen during smelting.
Manganese recycling happens mostly as a side effect of steel scrap recycling, with a smaller amount recovered from aluminum beverage cans. The overall recycling rate sits at about 37%, with an efficiency of roughly 53%. That means most manganese still comes from freshly mined ore rather than reclaimed material.
Manganese in Food
For most people, the practical answer to “where does manganese come from?” is food. Plants pull manganese from the soil, and it concentrates especially well in nuts, seeds, legumes, and leafy greens. Among common foods, the richest sources per serving are:
- Hazelnuts (dry roasted, 1 ounce): 1.6 mg, covering 70% of the daily value
- Pecans (dry roasted, 1 ounce): 1.1 mg, or 48% of the daily value
- Spinach (boiled, ½ cup): 0.8 mg, or 35%
- Soybeans (boiled, ½ cup): 0.7 mg, or 30%
- Sesame seeds (dried, 1 tablespoon): 0.2 mg, or 9%
- Kale (raw, 1 cup): 0.2 mg, or 9%
The adequate daily intake for adult men is 2.3 mg and for adult women is 1.8 mg. During pregnancy, the recommendation is 2.0 mg per day regardless of age. Children need less, ranging from 1.2 mg daily for toddlers up to 2.2 mg for teenage boys. A handful of hazelnuts and a serving of spinach at dinner would cover most of an adult’s daily needs without any effort.
How Soil Conditions Affect Supply
The amount of manganese available to plants depends heavily on soil chemistry, especially pH. Manganese solubility drops 100-fold for every one-unit increase in pH. That means alkaline soils, common in arid and semi-arid regions, often leave crops manganese-deficient even when the element is physically present in the ground. Calcareous (chalky) soils and poorly aerated soils also limit availability. Organic matter and moisture levels play a role too.
When crops can’t get enough manganese, the signs show up first on younger leaves as small yellow spots (in broadleaf plants) or grayish-green patches near the leaf base (in grasses and grains). The deficiency reduces photosynthesis, lowers chlorophyll levels, and cuts into root carbohydrate stores. Over time, it weakens a plant’s lignin production, especially in the roots, making them more vulnerable to fungal infections. For farmers, this translates directly into lower crop yields and reduced grain quality due to poor pollen production.
Manganese in Drinking Water
Manganese also enters your life through water. It dissolves naturally from rock and soil into groundwater, and at high enough concentrations it becomes a concern. The World Health Organization sets a provisional guideline of 0.08 mg per liter for total manganese in drinking water, chosen to protect the most vulnerable group: bottle-fed infants, whose developing nervous systems are sensitive to excess manganese. Even well below that health threshold, concentrations above 0.02 mg per liter can discolor water and stain laundry and plumbing fixtures. Standard water treatment methods can reduce manganese to below 0.05 mg per liter without difficulty.