The Instrumentation Center


ho box

Contributor: Judy Lynn Mohn Rosebrook

About the Display:ho The Holmium display features:

  • A Holmium coin from "The Elements Coin Series"-the coin is 3.8g and 99.5% pure! It is a first ever issue for Holmium in coin form (picture below!)
  • A Stockholm Coat of Arms patch representing the Swedish chemist, Per Theodor Cleve, who discovered Holmium in 1879. Holmium comes from the Latin word for the city of Stockholm, Holmia.
  • A photo of the Davis-Besse Nuclear Power Station located in Ottawa County, Ohio. Holmium can absorb neutrons, so it is used in nuclear reactors to keep a chain reaction under control. 
  • A magnetic pole piece with magnetic iron powder to demonstrate that Holmium has the highest magnetic strength of any element. Holmium is used in alloys for the production of magnets. 
  • 67 silver candles to represent the atomic number of Holmium, the year of Mrs. Rosebrook's Woodward High School graduation, and her age! 

Holmium is a Rare Earth metal, having a metallic sheen and is fairly soft and malleable. It rapidly oxidizes in moist air. It's magnetic properties could hold promise for future applications!

ho coin




Fun Facts:

  • Holmium is never found in its pure form in the wild!
  • Holmium oxide (Holmia) shows two dramatically different colors: yellow under natural light and pink under fluorescent lighting!
  • Holmium has medical applications: Holmium lasers emit light of a wavelength that does not damage eyesight, thus, one of its medical uses is for eye surgery!
  • Some of the most cutting edge lasers used to treat certain cancers are solid-state lasers that require Holmium to crack yttrium aluminum crystals. The lasers can be used to vaporize tumors with only minor tissue damage; a patient with early stage bladder cancer can be in and out of the hospital in an afternoon without a general anesthetic! A Holmium laser is pictured below:

ho laser

About the Contributor: judy From Judy: "I was born (in 1949, making me 67!!!) and raised in Toledo; attended Hamilton grade school, Woodward High School and received my Bachelor's Degree in Education from the University of Toledo! Married in 1973 to a farmer from Deshler in Henry County and have lived in his family home since then! Raised three children here and now have seven grandchildren! I retired from teaching in 2011 from the Patrick Henry School District, having taught Special Education, Learning Disabilities, 8th grade science, and language arts! I had read about this project in the Toledo Blade. Today there was an article in the Napoleon Northwest Signal about a local 2nd grader, Destiny Zamora, who had contributed. I thought, I would like to be a part of this also! I checked #67 and decided on Holmium!"

On why she chose Holmium: "I graduated from Toledo Woodward High School in 1967 and we are planning our 50th High School reunion this summer! Also, I'm 67!"

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Symbol: Ho

Atomic Number: 67

Atomic Mass: 164.93032 u

Electron Configuration: [Xe] 4f116s2

Year Discovered: 1879

Discovered By: Per Theodor Cleve

Last Updated: 6/27/22