Types of Stones

Stones are everywhere.  They're probably what you drove to work on, unless you live on oil rig, and there's a good chance at least part of your house is built on them.  Though despite their ubiquitousness, there are only three basic types of stones or rocks.

Three Types of Stones

Igneous

Igneous stone or rock is the most basic type of rock.  All rocks, in the beginning, were igneous rocks.  Igneous rocks are made up of cooled volcanic fluid, or lava.  They harden into igneous rock once they make it out to the earths surface or into the ocean.  Some types of igneous stone you might recognize are Granite, Obsidian, or Basalt. 

Sedimentary

Sedimentary stone is any type of stone that was once igneous or metamorphic and, through erosion, weathering, or chemical deterioration, turned into sand or clay and then became compacted or pressured into another, wholly separate rock.  This is sedimentary stone.  There is a lot of sedimentary stone on the surface of the earth, because due to weather, water, and wind, most rocks immediately start eroding when they get to the surface of the earth.  Some types of sedimentary stone you might recognize are limestone, sandstone, coal, or shale.

Metamorphic

Metamorphic Stone is a type of stone that is "morphed" from the other two types of rock, only unlike sedimentary stone, this does not involve eroding necessarily.  It is caused by the repressurization and heating of the rock, so that the old rock is pressed together with new ones.  Think of how marble has a multicolored aspect to it, and how if you look closely, you could see different individual rocks.  That's metamorphic.  Examples of this type of stone include slate, marble, and quartz.

Precious Stones

Stones are rarely differentiated from rocks in most regards, but one sense in which "stones" is usually used exclusively is in reference to so-called "precious" stones, which are stones that are shiny, striking, or beautifully cut to refract light.  They are typically used in jewelry.  The most famous of these types of stones is the diamond.  Diamonds are the hardest natural material known to man, and, though relatively common, have become enormously valuable in commercial markets thanks to a truly brilliant marketing campaign by the DeBeer's diamond company.

Birthday Stones

For whatever reason, someone once decided to assign different precious types of stones as "birthstones" for each month.  A few months get multiple birthstones, which I think is unfair.  Here is a list:

January - Garnet

February - Amethyst

March - Aquamarine

April - Diamond

May - Emerald

June - Pearl and Moonstone

July - Ruby

August - Peridot

September - Sapphire

October - Opal and Tourmaline

November - Yellow Topaz and Citrine

December - Turquoise, Blue Topaz and Tanzanite

Famous Stones

There are, surprisingly, a number of famous stones.  Here's a quick primer:

Blarney Stone

The Blarney Stone is a famous bluestone built into the Blarney Castle in Ireland.  There are several legends as to why that particular stone was put there, but none of them are very reliable.  The tradition of tourists in Ireland is to kiss the Blarney Stone for good luck.  Often, locals in nearby Cork tell tourists who have just returned from kissing the Blarney Stone that a common prank for drunken teenagers is to pee on the Blarney Stone.  The truth of this claim is questionable, but it has undoubtedly happened before. 

Plymouth Rock

For our purposes, we're not going to distinguish between rocks and stones.  Really, I think that's when life starts to get sad.  But yes, that's where the Pilgrims supposedly landed when they arrived in America.  It is uncertain whether this is actually the place where they got off the ship, as there aren't any references to it in primary sources, but it is on the shore of Plymouth Harbor, which is at the very least near where the Pilgrims landed.

The Black Stone of the Ka'aba

The Black Stone of the Ka'aba is a large, black stone situated at the east cornerstone of the Ka'aba, the single holiest site in Islam.  The stone was supposedly kissed by Muhammad, so when Muslims are performing their Hajj to mecca, it is customary for them to kiss the stone each of the seven times they circumambulate the Ka'aba.  No one is quite sure what type of stone it is.

The Hope Diamond

The Hope Diamond is a massive diamond that can be found in the Smithsonian.  Where it originally came from is unclear, but legend has it it came from a statue of Vishnu in India and, when stolen by looting colonists.  For this reason, it is believed to be cursed, as many of its owners (such as Marie Antoinette) have come to untimely deaths.

Stonehenge

A man-made formation of rocks created by the Druids which, as Eddie Izzard once declared, is "one of the largest henges in the world."  Stonehenge is somewhat mysterious, as the Druids did not keep records and because of its massive size.  Archaeologists believe the site was used for burials and ancestor worship.  The stones themselves are massive - up to 25 feet tall - and, like the Blarney Stone, are bluestones.  These bluestones supposedly came from Wales, which is not particularly close, in prehistoric terms, to the Stonehenge site.

The Rolling Stones

The best Stones of all.  The Rolling Stones are the world's greatest rock band.  They are from London, and were rivalled only by the Beatles during the British Invasion.  They really have nothing to do with actual stones, but one of their songs was called "Heart of Stone."  Their name came from from the name of a Muddy Waters song.  Another good song is Bob Dylan's "Like a Rolling Stone."  The concept of Rolling Stones - a rambler or vagabond or sorts - is incredibly popular in blues and early rock culture.

Another popular use of the word "stone" is in Stoner culture, in which "stoned" refers to being high, drunk, or otherwise intoxicated on some sort of narcotic.  The origin comes from the concept of "being stoned" or, as a punishment in old times, getting rocks thrown at you.  If you were to get hit by a rock (and weren't killed, obviously), you would be in a daze, much like a stoner.

It is not surprising that a material as basic and universal as stones have made it into pop culture in so many different ways.  So rock on.