Question

Which of the following silicon compound(s) is used for making ornamental objects?

• A. Zircon
• B. Carborundum
• C. Topaz
• D. Sand

Answer 1

Answer: (A), (C)

The correct options are
A Zircon
C Topaz

Zircon is an important gemstone of many colors, and is an historical gemstone used for thousands of years. Zircon is a mineral belonging to the group of nesosilicates. Its chemical name is zirconium silicate and its corresponding chemical formula is $ZrSi{O}_4$.

Topaz is a silicate mineral of aluminium and fluorine with the chemical formula ${Al}_{2}Si{O}_4{(F,OH)}_2$. Pure topaz is colorless and transparent but is usually tinted by impurities; typical topaz is wine red, yellow, pale gray, reddish-orange, or blue brown. It can also be white, pale green, blue, gold, pink (rare), reddish-yellow or opaque to transparent/translucent.