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Mirror Polished Solid Metal Cubes // Unusual Metals (Tier II)


Elemental metallic 1 cm elemental cubes

These highly polished cubes are great educational tools


Each cube is highly polished by hand and laser engraved with its periodic info.

  • Size: 10x10x10mm
  • Surface: Mirror Finish

*Each cube comes with an InvisiDisplay™ Case.

We brought you some interesting exotic metals in our TIER I, and now we are introducing you the unusual elements: Niobium, Tantalum, Hafnium, Rhenium, Thulium, Lutetium, and Scandium.

Each cube is solid and of high purity, highly polished by hand for many hours to reach a mirror finish, and laser engraved with the element's periodic info. This is an heirloom piece that will last forever.

Here are some interesting facts:

* Niobium(8.57 g/cm3): It got its name from the Greek goddess of tears Niobe. It is almost always found side by side with Tantalum in nature, they are interesting "indispensable twins". It is physiologically inert and hypoallergenic, used in prosthetic and implant devices, such as pacemakers.

* Tantalum(16.69 g/cm3): It is one of the refractory metals. Its melting point is exceeded only by tungsten and rhenium. It's highly corrosion-resistant and wildly used in aircraft engines, capacitors and laboratory equipment.

* Hafnium (13.31 g/cm3): It is highly corrosion-resistant. It does not exist in nature on its own but is combined with zirconium to form minerals. The low abundance and difficult separation techniques necessary make it a scarce commodity.

* Rhenium (21.02 g/cm3): It has the highest boiling point (5630 °C, 10,170 °F) and the third highest melting point (3186 °C, 5767 °F) of any element, wildly used in jet engines. It is one of the rarest elements in the Earth's crust.

* Thulium(9.32 g/cm3): It actually is the least abundant of the rare earth metals. It is soft enough to be cut with a knife. It has a bright silvery-gray luster. It's very difficult to make, we spend several hours just making one cube.

* Lutetium(9.841 g/cm3): It is only available in the Earth's crust at about 0.5 milligrams per kilogram. Lutetium is not widely used. It is only used for specific purposes. It has the highest Brinell hardness of any lanthanide, at 890–1300 MPa.

* Scandium(2.985 g/cm3): It is difficult to isolate in its pure form. It wasn't until 1960 that the first pound of scandium was produced. It is more abundant in the stars where it is around the twenty-sixth most abundant element.


  • Niobium: 8.5g, 99.9% purity
  • Tantalum: 16.6g, 99.95% purity
  • Hafnium: 13.3g, 99.6% purity
  • Rhenium: 21.0g, 99.99% purity
  • Thulium: 9.3g, 99.99% purity
  • Lutetium: 9.8g, 99.95% purity
  • Scandium: 2.9g, 99.9% purity

Polar Metals seeks to spice up your life with interesting and unusual metals in unexpected ways. The elements on the periodic table are everywhere, in fact, they make up everything!

So far, we have brought 29 Elements to you: Silver, Silicon, Germanium, Nickel, Chromium, Zinc, Niobium, Tantalum, Hafnium, Rhenium, Thulium, Lutetium, Scandium, Ruthenium, Platinum, Palladium, Gold, Iridium, Osmium, Titanium, Cobalt, Magnesium, Zirconium, Molybdenum, Copper, Aluminum, Carbon, Iron and Tungsten.

*Note: Please wear gloves when handling.

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