The short answer, maybe. The long answer, possibly?

Ceramic coatings have become a massive trend in the detailing industry. Ceramics, also known as a quartz coating and glass coating, are a suspension of Silicon Oxide (SiO) in a proprietary resin that cures and oxidizes as Silicon Dioxide (SiO2).  Silicon Dioxide has an Mohs hardness of 7 and a melting point of 1610 degrees Celsius.  Some coatings contain variations of polymers and Silicon Carbide (SiC) to alter the installation methods and hardness of the coating. But what does all this fancy specifications really mean to the average user? Not much.

Does hardness directly prevent scratches?

Not exactly. Hardness can help aid in some levels of protection, but on the scale of 1-3 microns which is the average thickness of a coating, it doesn't directly do much.  There is little to no evidence that coating hardness plays a role in scratch resistance. The elasticity of a coating and cross-link density plays a much greater role in scratch resistance. This has become a commonly misunderstood feature of coatings. Hardness is not the direct factor in how well a coating performs but rather the durability of surface energy and elasticity of a coating. 

What is surface energy and surface tension?

 Surface energy and surface tension go hand in hand when it comes to ceramic paint coatings.  Surface energy is a bit difficult to understand but it is "defined as the excess energy at the surface of a material compared to the bulk or the work per unit area done by the force that creates the new surface" (Source: TOGWT: Surface Energy) What that really means is there are two forces acting against one another, surface energy and surface tension. But what does this really mean to you? Well, the surface energy of a coating, when lower, will be much more hydrophobic. And this is a huge benefit of ceramic coatings, but not the key benefit. I highly recommend reading the above linked article for a really thorough explanation of surface tension that I cannot write better.

Does a hydrophobic coating protect more?

It does protect better, but it's the characteristic of being hydrophobic is not directly related to protection. Do not assume a surface is protected because it's hydrophobic, but rather its a benefit that can contribute to protection. Let's take for example three very dirty cars. Doesn't matter the color, but let's say black so we can paint a picture in your head. These three unloved and under appreciated Lamborghini Huracan's in Black. They are swirl free right now but are covered in built up break dust, dirt, salt, and road grime. Car #1 is coated in a hydrophobic ceramic coating, Car #2 is sealed in a hydrophobic polymer sealant, and Car #3 has zero protection and hasn't been polished in months.

We then proceed to wash all three cars using standard two bucket method. Car #1 cleans off perfectly leaving no major wash induced marring. Same goes for Car #2. Car #3 on the other hand retained such a significant amount of dirt, it required much more aggressive washing and time. Now one would say, if the detailer are washer knew what they were doing, all three cars will be swirl free. But the worlds not perfect and neither is the owner of all 3 Black Lamborghini Huracans (who in their right mind would buy not 1 but three in the same color?).

Why is car #3 have more wash induced marring? Is it because the hardness of the ceramic coating protecting #1? Well #2 has no swirls either, so that can't be the direct cause. It's the surface energy of the coated surface and the same goes for Car #2. The surface of the sealed car has molecules that are much weaker than those of the water molecules and because they are weaker the water molecules retain their positions and ultimately remain in a more solid water droplet form. And because of this, the coated AND sealed surfaces become much easier to wash, removing dirt with less effort and scrubbing and also rinsing away much more water which then means less drying. The less contact with the surface, the less likely there will be wash induced marring.

So how does a coating then protect?

 How a coating protects your vehicle is through two factors. One, it's low surface energy which allows for easier cleaning of the surface and much less retention of dirt when compared to traditional wax. A high quality ceramic coating will outlast any traditional wax and will also outperform. The durability of coatings is constantly increasing. Many coatings can resist chemicals that would normally removed any and all protection from a surface. The second benefit of a ceramic coating is that when properly installated, which generally means a certified installer who has years of experience, a coating can build very durable thickness. This thickness, when paired with a flexible coating can provide protection against elements and abuse. But the thickness of a coating generally is only 1-3 microns. Even when layered in multiple layers, the coating thickness can still be less than 3 microns as layering can remove the previous coats. Multiple layers after 3-4 can actually reduce the gloss as a coatings pure clarity is less then that of quality clear coat. But we will discuss clarity of gloss of coatings in a later article. When properly installed at the correct thickness a coating will dramatically improve the appearance of a vehicle while also outlasting any other gloss enhancing product on a market.