When judging rubies from photographs, one can separate then into two main characters the Mild and the Wild. With this short-cut, we will be able to extract some basic rules for an otherwise unmanageable multitude of ruby varieties.

Mild rubies exhibit a dense red glow with introverted, rich and earthy colors. Such a ruby can vary from fire engine (red-red) to rose red (add some purple) to an earthy crimson red (add some brown). Highest prices are paid for fire engine red, with rose red and then crimson following. Brownish brick red rubies are the most reasonably priced. When purchasing a mild, insist on at least one image with light in the back. Mild colored ruby will easily hide inclusions from the camera. Make sure the image does not only focus on the surface of the stone. A mild ruby needs an image with light falling in from the back of the gem. This will show you inclusions with all honesty. Many images on the web are "front-loaded". They show only the surface of the gem but not the inside. This is done to peddle translucent, or even opaque, cabochon quality as facet grade ruby. Above all else, a mild colored ruby needs clarity. Heavily included ruby in mild colors looks dull in person. The value of such cabochon quality corundum is negligible in comparison to transparent ruby (unless it displays a star ruby of course). The scarcity of good material has somewhat lowered the bar to what is labeled as facet-quality ruby. A translucent or opaque mild ruby might look OK on the photo, but the stone will be boring in person and have zero luster. Clearly, these are not good qualities in a stone. Ruby is by nature more included than, say, tourmaline. You will only get a "free of inclusion" if you have very deep pockets. However, some inclusions are wanted, while others are to be avoided.
Fine silky needle structures are delightful, shattering light rays into a hypnotic gleam. Thicker needles are interesting under the lens and do little harm to beauty. Less attractive, and hence price reducing, are whitish clouds, visible black spots, growth lines with weak color zones or broken crystals. While mild ruby will swallow its inclusions, it will also hide its luster and no high-end camera can change that. However, even the worst cut ruby has luster as long as it is clean. Unfortunately, it is often impossible to capture this on photo. Hence, in mild ruby photos, you need to be picky with inclusions but may be generous with luster and radiance. A pleasant mild ruby will never disappoint as long as it is clean.

The rubies that can labeled as wild exhibit flamboyant neon radiation in a flashy and energetic red. Often described as "neon", "vivid" or "electric", these rubies may have a good deal of purple, pink and violet in them, yet their main feature is a radiant, almost aggressive red. Such a ruby will always catch your attention. It will stand out, even in a shop window loaded with other gemstones. They are the masters of the red universe. No other material (man-made or natural) can beat them. Some flowers come close, but of course they lack fire and glow. The three most important qualities of a wild ruby are color, color and color. Ferociously red rubies are found in Ceylon, Vietnam and Africa, but rarely. Burmese rubies, on the other hand, are often on the wild side. (The craziest ones are coming from Namya these days.) Wild Burmese rubies have been worshipped for millennia. They are the fame of Burma and are extremely costly. Most jewelers, and even many dealers, have never seen one. Most mortals actually never get to see anything but mild colored cabochon quality. Mild colored opaque ruby is the standard in jewelry. Others have shed many words to describe high-end rubies, so I won't try any longer. Nothing beats the eye-to-lens sensation of a buster neon ruby, but a good image will get your appetite started. The best wild rubies separate violet and purple from red. The magic of ruby comes from the ruby-only ability to mingle blue/violet into red and then set it aflame in radiation. Some pink and purple sapphires can do the same trick but red spinel never does. In straight sunlight, many good wild rubies will show themselves more like a blob of red gleam. Though this is a sign for a good gem, it is not enough. With light intensity reduced to a manageable amount, blue/violet and purple will separate from the red. This might look like color-zones, but it is exactly what you want: A digital separation of blue/violet from red (with purple and pink in-between) is the best indicator for intense red ruby. For wild rubies inclusions are only a secondary concern. Color is king. A neon ruby can easily be moderately included without looking dull. Even in translucent material a neon red is still very attractive and many budgets will be limited to more or less included material. Translucent rubies are OK as long as the color is extra terrific and the price right. A fine wild ruby never holds still on an image. Something always seems to be moving in them. Often it looks as if a flickering fire or a hot swirling fluid is caught in the gem. As if there is something alive in them. However, beware of digital enhancement. Since color is the name of the game, some are tempted to "improve" their pictures for the web. Avoid "super bargains", plastic-like hues, and check the photos background: It should be neutral and real (the gem should not be "cut-and-pasted" into a new background). Light conditions should be normal (mixed light, filtered sunlight). Tungsten light alone is not enough. Ask for images in different light settings and angles. One can't easily repeat a faked or stolen photo in variations.

Regularly discussed is the line between pink/purple sapphire and ruby. Yes, pink is a pale red but only what is independently certified as ruby can be sold as ruby. All else is wishful thinking of the seller. Period. You may trust a third party laboratory to draw the line between red and pink. They are professionals, have no stake in the classification and will not risk their jobs for favors. Rich purple or hot pink sapphires can be as extra-terrestrially glowing as ruby. Here Ceylon is even better than Burma, which makes sense given that Sri Lankan ruby tend to be more on the pink side too. Deep neon purple or pink
sapphires are terrific alternatives to ruby and are not that expensive, yet.