Scandium is not a metal you will work with every day. It is a rare element on Earth and not an easy metal to find. Calcium and potassium are much more common if you went out looking.
Scandium was discovered in 1878 by a chemist named Nilson who was studying several minerals in Europe. In fact, scandium is always found bonded to other elements. Jewelers know about scandium because it is an important element in aquamarine crystals and gives them their blue color. When isolated, scandium looks just like the other silvery-white colored metals.
Scandium is the first element of the period table where electron configurations start getting a little wild. It is the first of the transition metals and we talk about how the electrons are positioned in the 'shells' page.
Where else can you find scandium?
Aquamarine
You'll find a wee bit of scandium in the semi-precious gem aquamarine. It's also found in a few other rocks and minerals found on Earth.
Industrial Lights
Ever go to a big indoor sports event? Or a convention center? Or a warehouse? There's a good chance that those big industrial lights have a little bit of scandium in the bulbs.
Alloys
As with most of the transition metals, they appear in one alloy or another. It's kind of like a blanket statement that metals are in at least one alloy in trace amounts.