Quartz

A quartz clock is a clock that uses an electronic oscillator that is regulated by a quartz crystal to keep time.

More information...

Buckle

The pin buckle is a locking mechanism for bracelets. Holes are punched into one, longer part of the bracelet, at the end of the other is the actual buckle. The buckle itself consists of a pin that passes through the hole to fix the desired length, a spring bar and a U-shaped metal shackle that prevents the pin from slipping out of the hole again.

Charcoal

Anthracite is the most metamorphosed type of coal (but still represents low-grade metamorphism), in which the carbon content is between 92% and 98%.[2][3] The term is applied to those varieties of coal which do not give off tarry or other hydrocarbon vapours when heated below their point of ignition. Anthracite ignites with difficulty and burns with a short, blue, and smokeless flame

More information...

Sapphire glass

One application of synthetic sapphire is sapphire glass. Here glass is a layman term which refers not to the amorphous state, but to the transparency. Sapphire is not only highly transparent to wavelengths of light between 170 nm (UV) and 5300 nm (IR) (the human eye can discern wavelengths from about 380 nm to 750 nm[33]), but it is also five times stronger than glass and ranks a 9 on the Mohs Scale, and much tougher than tempered glass.

More information...