Periodic Table

Holmium

Lanthanide

Quick Facts about Holmium

Dy
  • solid- state of matter at room temperature
  • Stable- has at least one stable isotope
  • +3- common oxidation states in compounds
  • HEX- crystal structure, atomic arrangement in solid form
Er

Holmium (Ho) is element 67 on the periodic table. Atomic mass of Ho: 164.9300 u. Ho is in period 6. Melting point of Ho: 1734.00 K.Density of Ho: 8.79 g/cm³.

Why Holmium Matters

Holmium in everyday life and industry

In Your Home

  • Strong magnets use holmium for magnetic flux concentration
  • Microwave equipment may contain holmium garnets

Industry Uses

MedicalHolmium lasers are used for medical surgery
NuclearNuclear reactor control applications use holmium

In Your Body

✗ Not essential

Holmium has no known biological role. Holmium lasers are used in urology and other surgeries. Ho-166 is researched for cancer treatment.

Safety: Generally considered to have low toxicity

Discovery of Holmium

Discovered by J.L. Soret in Switzerland, 1878

Name origin: From Holmia, the Latinized name for Stockholm, Sweden.

History & Events

1878
Named after Stockholm (Latin: Holmia)
1878
Discovered by Marc Delafontaine and Jacques-Louis Soret in 1878
1878
Independently found by Per Teodor Cleve who named it
1878
Has the highest magnetic moment of any naturally occurring element

About Holmium

Relatively soft and malleable silvery-white metallic element, which is stable in dry air at room temperature. It oxidizes in moist air and at high temperatures. It belongs to the lanthanoids. A rare-earth metal, it is found in the minerals monazite and gadolinite. It possesses unusual magnetic properties. One natural isotope, Ho-165 exists, six radioisotopes exist, the most stable being Ho-163 with a half-life of 4570 years. Holmium is used in some metal alloys, it is also said to stimulate the metabolism. Discovered by Per Theodor Cleve and J.L. Soret in Switzerland in 1879. The name homium comes from the Greek word Holmia which means Sweden. While all holmium compounds should be considered highly toxic, initial evidence seems to indicate that they do not pose much danger. The metal's dust however, is a fire hazard.

Atomic Properties of Ho

Atomic Number of Ho
67
Atomic Mass of Ho
164.9300 u
Electron Configuration
[Xe] 4f11 6s2
Electronegativity
1.23
Block
f-block
Group
—
Period
6

Physical Properties of Ho

Phase (STP)
solid
Melting Point of Ho
1734.00 K
Boiling Point of Ho
2873.00 K
Density of Ho
8.7900 g/cm3

Thermal Properties

Heat of Vaporization
301.00 kJ/mol
Specific Heat
0.17 J/g·K
Molar Heat Capacity
27.15 J/mol·K

Atomic Radii

Calculated
175 pm
Covalent
166 pm
Van der Waals
230 pm

Common Misconceptions

Wrong:Holmium is named after a scientist like many elements.
Correct:Named after Stockholm, Sweden (Latin: Holmia). Per Teodor Cleve, a Swede, chose the name to honor his country's capital.
Wrong:Highest magnetic moment means holmium makes the best permanent magnets.
Correct:High magnetic moment ≠ good permanent magnet. Holmium's magnetism isn't stable at room temperature. NdFeB (with Dy) works better for permanent magnets.
Wrong:Holmium has no practical medical applications.
Correct:Ho:YAG lasers are standard in urology—they fragment kidney stones and perform prostate surgery. Ho-166 microspheres treat inoperable liver cancer.

Isotopes of Holmium

Holmium has 1 naturally occurring isotope, plus 1 notable radioactive isotope.

IsotopeAtomic Mass (u)AbundanceHalf-LifeDecay Mode
16567Ho (Ho-165)Holmium-165 isotope164.9303288100.00%——
16667Ho (Ho-166)Holmium-166 isotope165.93229090%26.8 hoursβ⁻

Data source: NIH PubChem (aggregated from IUPAC, NIST)

Isotope Applications

Isotopes of Holmium have important real-world applications in science and industry.

Medical Applications

Radiosynovectomy with 166Ho-radiopharmaceutical agents can be used for treatment of arthritis. The half-life of 166Ho is 1.1 days. 166Ho ferric hydroxide macroaggregate ([ 166Ho] FHMA) radiosynovectomy is being used because FHMA minimizes extra-articular (outside a joint) leakage of the radioisotope [472], [473]. 166Ho has been used for radioimmunotherapy (RIT) with labeled antibodies [474]. The 166Ho-chitosan complex (a linear polysaccharide, which is a long-chain molecule like cellulose that is used by the body for energy storage) is being used for hepatic (liver) cancer therapy [475]. 166Ho-labeled radiopharmaceuticals have been used for alleviating pain from bone metastases [443], [473], [476]. 166Ho microspheres have been used for intra-arterial radioembolization (treatment where radioactive particles are delivered to a tumor through the bloodstream) of liver metastases (Fig. IUPAC.67.1) [475]. 166Ho is paramagnetic and emits both beta and gamma radiation, which makes it ideal for radioembolization. These properties also enable the distribution of 166Ho microspheres to be visualized with magnetic resonance imaging and single-photon emission computed tomography (SPECT) [475]. The 166Ho-Patch is a specially designed radioactive skin patch that is used for external radiation of superficial skin cancers and Bowen’s disease in areas that are sensitive and difficult to treat by methods that are more destructive and have poor cosmetic results (i.e. areas of the face) [477], [478].

Abundance

Earth's Crust
1.3 mg/kg
Seawater
2.20×10-7 mg/L

Uses

Ho:YAG lasers are workhorses in urology (kidney stone fragmentation, prostate surgery). Holmium's high magnetic moment makes it useful for creating intense magnetic fields. Ho-166 microspheres treat liver cancer.

Sources

Occurs in gadolinite. Most often from monazite which is often 50% rare earth and typically 0.05% holmium.

Geochemistry

Goldschmidt
litophile
Geochemical Class
rare earth & related

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