Rarest stable metal
Osmium occurs only in tiny amounts as a companion of platinum — rarer than gold or platinum.
Basics
Osmium is a chemical element with the symbol Os and atomic number 76. It is the densest of all elements (22.59 g/cm³) and the rarest stable metal on Earth. Osmium belongs to the platinum metals and is traded in crystalline, forgery-proof form.
Fact sheet
| Chemical symbol | Os |
| Atomic number | 76 |
| Density | 22.59 g/cm³ — densest of all elements |
| Melting point | approx. 3,033 °C |
| Boiling point | approx. 5,012 °C |
| Element group | Platinum metals (platinum group) |
| Colour | bluish-silver shimmer |
| Discovery | 1803 by Smithson Tennant |
Highest density: at 22.59 g/cm³ osmium is the densest known element — denser than gold (19.3), lead (11.3) or platinum (21.4). A small piece weighs surprisingly much.
Bluish-silver shimmer: in crystalline form osmium shows a characteristic blue-silver shine that sets it apart from every other precious metal.
Safe in crystalline form: while fine osmium powder can form toxic osmium tetroxide when oxidising, the crystalline investment osmium is stable and safe to handle — and that is the form being traded.
Extremely hard & durable: osmium is very hard and corrosion-resistant — properties once used for alloys such as fountain-pen tips.
Why so special
Osmium occurs only in tiny amounts as a companion of platinum — rarer than gold or platinum.
22.59 g/cm³ — no other element on Earth is denser. High value in the smallest of spaces.
Ranking of the densest metals →The unique crystal surface acts as a physical fingerprint (OIC).
Tradable in crystalline form since 2017 — with a marked price development.

Historically osmium was used mainly in hard alloys — for pen nibs, bearings and instrument needles. Today a different role dominates: osmium as a precious metal and store of value, as well as exclusive osmium jewelry.
Thanks to its crystalline, certified form, osmium has become forgery-proof — the basis for it being traded today as an investment at a set price.
From knowledge to entry:
See certified osmium → AdOutlook
Beyond jewelry and investment, osmium is increasingly viewed as a material for high technology. In an especially high-purity, fine-granular powder form – as HighTech-Ready Osmium (HTRO) with purity grades from 99.99% to 99.99999% (4N–7N) – the metal is being researched for possible future applications: second-generation quantum computing, medical technology, high-temperature superconductivity and semiconductor technology. Crystalline osmium itself is used primarily as an investment and for jewelry; for industrial use it first has to be converted into the high-purity HTRO powder form.
FAQ
Osmium (symbol Os, atomic number 76) is the densest of all elements and the rarest stable metal on Earth. It belongs to the platinum metals and is traded in crystalline, forgery-proof form.
22.59 g/cm³ — making osmium the densest of all known elements, denser than gold, platinum or lead.
Crystalline, metallic osmium is stable and safe. Toxic is mainly osmium tetroxide, which can form from fine powder — not the crystalline investment form.
It occurs only in tiny amounts as a companion of platinum; extraction and crystalline processing are extremely complex.
Read on
The ranking of the densest metals, the narrow lead over iridium and why “heavy” and “dense” are not the same thing.
See the ranking →HighTech-Ready Osmium (HTRO): high-purity osmium for quantum computing, medical tech & superconductivity — still research.
High-Tech & HTRO →Check the current price or buy certified osmium directly.