- Shilajit is an exudate: it seeps from layers of rock.[1]
- Its organic part comes from plant and microbial metabolites in the “rock rhizosphere”.[1]
- Microbes play a central role, but the full formation process isn’t yet understood.[2]
- Formation explains both its humic chemistry and its variable mineral and contaminant content.[3]
The three ingredients: plants, microbes and rock
Researchers describe shilajit as a complex mixture of organic humic substances and plant and microbial metabolites, occurring in the rock environment where it forms.[1] Each of the three ingredients leaves a fingerprint:
| Ingredient | Contribution | Seen in the finished resin as |
|---|---|---|
| Plant material | Raw organic matter | Humic substances, including fulvic acid |
| Microbes | Break down and transform the plant matter[2] | Microbial metabolites and humification products |
| Rock | Minerals and trace elements | The mineral profile, including unwanted metals |
Step by step: from plant matter to resin
- TrappingPlant matter collects in cracks and layers of rock.
- HumificationMicrobes slowly convert it into humic substances.
- BindingThe humic material binds minerals from the rock.
- ExudationWarmth softens the material and it seeps out of the rock.
A simplified model; deposits may form in different ways.
What “humification” means
Humification is the process that turns dead plant matter into humic substances, the same family of compounds found in soil and peat. These substances are grouped by solubility into fulvic acid, humic acid and humin, and they make up the bulk of shilajit’s organic content. See humic substances explained and fulvic acid in shilajit.
What isn’t known
A 2019 literature review emphasised the role of microbes in shilajit’s formation, and noted major gaps in understanding of the material more broadly.[2] In particular, there is no reliable dating of how long commercial deposits take to form. Claims that a resin “took centuries to form” can’t be checked and shouldn’t be read as a quality marker.
Why formation matters to buyers
- Every deposit is differentLocal plants, microbes and rock create different compositions; see why composition varies.
- Rock minerals include metalsShilajit absorbs whatever the rock contains. A 2025 study found thallium in shilajit and supplements.[3]
- Testing beats geologyBecause formation varies, batch testing tells you more than any origin story; see laboratory testing.
What formation tells you about appearance
Because shilajit forms from different plants, microbes and rock in each location, raw material varies from pale brown to blackish brown, and from runny to almost solid.[1] After purification, most commercial resin is dark brown to black and glossy. That’s why colour and texture can’t identify a source or prove quality on their own; see what shilajit looks, smells and tastes like and texture and colour checks.
Frequently asked questions
Is shilajit a plant, a mineral or a rock?
None of these exactly. It is an organic-mineral exudate: organic humic material from decomposed plants and microbes, combined with minerals from the rock it forms in.[1]
Why does shilajit seep out of rock?
The material softens in warm conditions and flows out of cracks and layers in the rock, which is why collection usually happens in warmer months.
How long does shilajit take to form?
Nobody knows reliably. There is no published dating of commercial deposits, so “formed over centuries” claims can’t be verified.[2]
Does shilajit form anywhere other than the Himalayas?
Yes. It is reported in many mountain ranges, with the Himalayas and Hindu Kush most often named.[1] See where shilajit comes from.
Why can shilajit contain heavy metals?
Because it binds elements from the surrounding rock as it forms. That’s why batch testing for metals matters; see heavy metals in shilajit.
Is shilajit a fossil?
No. Shilajit is formed from decomposed plant matter transformed by microbes and combined with rock minerals; it isn’t fossilised remains.[1]
Is shilajit renewable?
It forms slowly, and there is no reliable data on how quickly deposits replenish, so it is best treated as a finite natural resource.
Sources & further reading
Primary research, regulators and standards bodies are cited first. A source being listed here does not mean it supports every claim made by sellers; it supports the specific statement it is attached to.
- Agarwal SP, et al.. Shilajit: a review. Phytotherapy Research 21(5):401–405, 2007. doi:10.1002/ptr.2100; PMID 17295385. View source (opens in a new tab) [Review]
- Shilajit (Mumie): current status of biochemical, therapeutic and clinical advances. Current Nutrition & Food Science 15(2), 2019. doi:10.2174/1573401313666170823160217. View source (opens in a new tab) [Review]
- Quantifying of thallium in Shilajit and its supplements to unveil the potential risk of consumption of this popular traditional medicine. BMC Chemistry 19:20, 2025. doi:10.1186/s13065-025-01384-7. View source (opens in a new tab) [Laboratory analysis]