This is a good starting place to learn about some of the most common words you will hear when beginning to collect Megalodon teeth and other related sharks teeth.
In this first picture below we will take a look at a very high quality Megalodon Shark Tooth from the Lee Creek Mine in Aurora, North Carolina, USA and get down to some basic nomenclatures. The quality below is just about as good as it gets. This is a Megalodon tooth with no major flaws, which is a good starting point for how a Megalodon tooth should look in a perfect world. From here let's start sliding down the tooth from root to tip and give some examples of flaws one might encounter and the wording that is most commonly used to describe these flaws.
Starting with the root, I think it is best to begin by demonstrating what an almost perfect root should look like. The Megalodon tooth's root below is of exceptional quality, even with some superficial cracks running through it. Can you find a completely flawless root with no cracks? Yes, they are out there but 9 out of 10 times they will be on a much smaller tooth. These lines are often referred to as "expansion cracks" and they are beyond common. On the tooth above, the nutrient holes represent where the blood vessels went into the tooth, giving it a blood supply. These are not flaws...nor do they add any real monetary value to the tooth. Some teeth have some fairly pronounced nutrient holes and some do not. It's not a game changer either way. The Megalodon tooth above has some pretty obvious nutrient holes while the Megalodon tooth below does not.
Next we will take a look at root pitting and root erosion. I added "bourlette flaking" into the diagram but emphasis is on the root flaws at this point. Root pitting is just that....small individual pits in the root. Pitting can turn into erosion and some teeth will exhibit pitting only, others erosion only, and then some will exhibit both as in the picture below demonstrates.
Continuing down the tooth we come to the bourlette. The next two Megalodon teeth below are what I would consider to be as close to perfection as one can realistically expect when it comes to the bourlette region.
Next is a bourlette with a small line of separation between the bourlette itself and the enamel. In a perfect world the bourlette would flow seamlessly into the blade but this is so hard to find that it's an unrealistic expectation for most collections. A small line of separation is beyond common and very acceptable.
The next few pictures speak for themselves in terms of bourlette flaking, which is not an exact science. It's simply looking at the tooth and guesstimating the amount that is missing.
The bourlette on the Megalodon tooth below is totally washed out.
Next we move to the enamel with enamel peel being the most common and most brutal flaw to this part of the Megalodon Tooth. Enamel peel almost always begins just below the boulette region and works its way down the shark's tooth.
Enamel peel runs the full spectrum from slight peel just below the bourlette to visually destroying the entire shark tooth.
Next we look at a large Bone Valley Megalodon shark tooth with flawless serrations. This shark tooth also has some blade wrinkles, but this characteristic is not a flaw nor an asset.
Serration and blade damage can be caused by three primary ways.
1) During feeding. This can be caused when the shark bites down on the bones of its prey. It is believed that whales were the Megalodon shark's primary source of food and whale bones are very hard in nature.
2) By biting down on the sharks own teeth. This is also caused during feeding but is caused by its own bite force versus the hard bones of its prey.
3) In fossil sharks teeth, such as Megalodon teeth, damage to the blade can come from simply rolling around on the bottom of the ocean floor or river bed. Damage can also come from the tools used to dig them out of the sediment or clay on land.
Below is an example of a Megalodon shark leaving bite marks on its own tooth.
Although impossible to know for sure the source of the nick to the blade below, it is almost always described as either feeding damage or feeding wear.
Below the feeding damage/wear gets progressively worse to these Megalodon Teeth.
Next we will go from a Perfect tip, to tip serrations nicked, to tip damage.
And lastly, we will take a look at the average quality Megalodon shark tooth that is discovered. The overwhelming vast majority of Megalodon teeth that are found are in terrible condition...with multiple flaws. The Megalodon shark went extinct around 2 million years ago, which means each of these teeth have been laying in the ground for at least that long. Erosion, wind, fast moving water, all take a toll on anything that is left to the elements and mother nature. High quality Megalodon teeth are the extreme exception...not the norm. Below is an example of your average quality tooth that is found.