The late Donald J. Borror was a professor of zoology and entomology at Ohio State University who penned a little book for biology students entitled Dictionary of Word Roots and Combining Forms. The subtitle is the remarkably descriptive Compiled from the Greek, Latin and other languages with special reference to biological terms and scientific names.

It’s one of my essential references.

According to Borror beryll– is Greek for “sea-green jewel.” Here’s a picture of aquamarine, a form of the mineral beryl:

Another form of beryl is emerald, a precious stone known since antiquity. Beryl (beryllium aluminum silicate, Be₃Al₂Si₆O₁₈) is, like all beryllium compounds, toxic. You can wear your emeralds without fear of being poisoned as the mineral is an insoluble, very hard, and stable cyclo-silicate. But if you are digging the stuff up and processing it (including cutting and polishing) you have to be careful.

The pure element is not found in nature. It is a column II metal (alkaline earths) like Magnesium (Mg, #12) and Calcium (Ca, #40) and is thus highly reactive. Both Ca and Mg are abundant in the earth’s crust but only in compounds. Be is much rarer despite its worldwide distribution. And we know that Ca and Mg are essential nutrients for humans. Be and its compounds, especially the salts, can be deadly in small amounts and at low concentrations.

Beryllium is used in countless alloys and finds many applications in the aerospace industry. It makes both copper and aluminum stronger and less prone to sparking and thus is desirable for specialized tools. It is transparent to X-rays and is used extensively in those devices. But care must be taken in refining, manufacturing, and handling due to the ready absorption by the body of dust and fumes.

Only a few hundred metric tons of beryllium ore (mostly beryl) are mined annually, most of that in the United States.