Ok so I was mining and i bumped into a silverfish stone! The strange thing is it took longer to break and it was NOT near a stronghold. Just wondering if silverfish spawn in random places now or still just strongholds?
They now also very rarely spawn in Extreme Hills biomes. Approximately an average of 1 per chunk.
The time they take to break should be exactly the same regardless of tool. This means that if you use a diamond pick, breaking a stone block is normally almost instant, but breaking a silverfish block will take a second - same as if you used your fist. This is useful for helping to identify silverfish blocks. If you're just mining along, and one block seems to be taking a little bit longer to mine - stop. It might be silverfish block. Punch it with your fist to see if it starts breaking faster than a normal stone block.
As I have read on the wiki, they take as much time to mine as wool, unless that was changed.
Tested and confirmed. Unless you are using shears, in which case wool drops faster.
I thought silverfish blocks took longer to break with a pickaxe than by hand?
No. You probably misunderstood the wiki. Silverfish blocks take longer to break with a pickaxe than normal stone blocks (except a wooden pick, which takes about the same time). Silverfish blocks break faster by hand than normal stone blocks. However, Silverfish blocks take the same amount of time to mine by hand or by pickaxe. Try it out yourself if you'd like - I just did.
Found naturally generated Silverfish blocks in Minecraft Snapshot 12w38a. To find it, I used MCEdit to remove rock, dirt, gravel, etc. from a large area of a 12w38a world and searched for Silverfish blocks. Upon using Re-Create world option to find it without removing the terrain, I found that the Silverfish blocks were in fact not attached to any cave system, although apparently near one. So these can be found buried anywhere.