Slate is a metamorphic rock. A rock that undergoes great heat and high pressure is changed into a metamorphic rock. The original rock was deep in the earth where it was exposed to magma which produces heat up to 800 degrees Celsius. Pressure comes from layers on top of layers of rock. After millions of years of heat and pressure, the end product is a metamorphic rock. Through uplift and erosion the metamorphic rocks eventually end up on the crust of the earth.
Slate is a metamorphic rock which has a very fine grain and contains micas and chlorites. The parent rock of slate is shale. Slate can be blue, purple, green and varying shades of grey. Sometimes fossils and microscopic remains of organisms can be found in slate
Small pieces of slate with a wooden frame where used for writing by school children in the 1800s. Small pencils were made of slate or clay to write on the slate boards. A soft cloth was used to clean the slate. Slate can be broken into sheets which allowed it to be used as a building material. Slate from Spain is used as roofing in ninety percent of Europe. Slate is an excellent roofing material because it is resistant to breaking from freezing temperatures and only absorbs less than 0.4% of rain water. Slate roofs have a lifespan of up to 100 years.
Because slate is fireproof and a good electrical insulator, it was used to construct electric switchboards in the early 20th century. It was also used for relays in large electric motors. Slate is thermally stable and is still used for laboratory bench tops. High quality slate is used for tombstones. President John F. Kennedy’s tombstone is made of slate.
Slate artifacts have been discovered in more than three dozen Mayan sites in Belize. The Mayans drilled, sawed, and beveled slate. Slate was used to make circular or rectangular funerary contexts for the elite and royal Mayans. Mayans also used slate to make ceremonial maces, figurines, game boards and large lidded vessels. Maya stelae are monuments of tall sculpted stone shafts found throughout the Maya kingdom produced from 400BC to 900. In the Mayan city of Tikal, black slate was imported more than 200 miles from the Maya Mountains. The blocks of stones had to be transported on rollers because Mayans lacked beasts of burden and did not use the wheel. The main purpose of the stelae was to glorify the kings of cities. The stela portrayed the king’s wealth, ancestry, and prestige.
Today slate is used for flooring, walkways, patios, sinks, turkey calls, billiards tables and stones to sharpen knives. Slate is still used for roofing. Slate is popular in landscaping. Counter tops can be made of slate. There is slate furniture, and slate fireplaces.
In conclusion, slate is a metamorphic rock made of micas and chlorites. Slate can be found in a variety of colors. It is valued for its beauty and thinness. Slate was used by the ancient Mayans thousands of years ago and is still used today for roofing, home products such as fireplaces and countertops, and in landscaping yards with slate patios and walkways. Slate is durable and will continue to be used in various products in years to come.
