Okay, first let me state that I am aware that I might be talking rubbish, but I was focusing on this the last few days, and the results are pretty consistent so I decided to share so someone else can confirm or debunk it. (Or tell me it is already common knowledge.... 
I spotted an interesting pattern while hunting for some rarer materials. As you drive around, every time you shoot an outcrop/meteorite/whatever, as I understand it, another one is spawned in your vicinity. Usually within the range of your scanner.
This has an interesting implication. If you focus on only one type of outcrop, you are more likely to spawn the same type as the one you just shot apart.
Not always, but the longer you keep destroying the one type, the more likely it is that more of them will appear nearby.
Another observation is that certain materials only spawn in certain outcrop types (obviously, but it is not true for the common mats - those can appear wherever they want.)
This kind of spawning behaviour is becoming exponentially awesome, if you keep doing it long enough.
Example, yesterday I was lucky and within ten minutes I found a Mesosiderite that had and Iron, Tungsten and Technetium inside. (Yay! I need Technetium) So I kept on shooting only mesosiderites, ignoring all other outcrops and other stuff. For the next half an hour the ratio of mesosiderites to other things kept rising to the point when I had at least three of them within a kilometer at all times. Then, within the last 20 minutes of my planetary operation, I basically had a radar full of them and I collected 12 units of technetium and over 20 units of Tungsten.
So I would like to propose an experiment, for whomever is interested. Once you find a rare mat that you're after (as we know there's only one on each planet, so if you find the one you don't need, change the planet) keep shooting only the outcrop type you've found the thing in for next 30-40 minutes.
We'll see if I should report it as a bug in my game, or if it's an actual thing.
I am conflicted about this, to be honest. On one hand, yay! Loads of technetium! - On the other hand, it does scream "exploit!" quite unpleasantly.
I spotted an interesting pattern while hunting for some rarer materials. As you drive around, every time you shoot an outcrop/meteorite/whatever, as I understand it, another one is spawned in your vicinity. Usually within the range of your scanner.
This has an interesting implication. If you focus on only one type of outcrop, you are more likely to spawn the same type as the one you just shot apart.
Not always, but the longer you keep destroying the one type, the more likely it is that more of them will appear nearby.
Another observation is that certain materials only spawn in certain outcrop types (obviously, but it is not true for the common mats - those can appear wherever they want.)
This kind of spawning behaviour is becoming exponentially awesome, if you keep doing it long enough.
Example, yesterday I was lucky and within ten minutes I found a Mesosiderite that had and Iron, Tungsten and Technetium inside. (Yay! I need Technetium) So I kept on shooting only mesosiderites, ignoring all other outcrops and other stuff. For the next half an hour the ratio of mesosiderites to other things kept rising to the point when I had at least three of them within a kilometer at all times. Then, within the last 20 minutes of my planetary operation, I basically had a radar full of them and I collected 12 units of technetium and over 20 units of Tungsten.
So I would like to propose an experiment, for whomever is interested. Once you find a rare mat that you're after (as we know there's only one on each planet, so if you find the one you don't need, change the planet) keep shooting only the outcrop type you've found the thing in for next 30-40 minutes.
We'll see if I should report it as a bug in my game, or if it's an actual thing.
I am conflicted about this, to be honest. On one hand, yay! Loads of technetium! - On the other hand, it does scream "exploit!" quite unpleasantly.