Fake Hong Kong And Straits Settlements Silver Coins?

There's a couple of things you could do to check. Try running a magnet over the coins. If they stick to the magnet, they're fake. Another easy thing you can do is to check the coin alignment. If you hold the coin looking at the queen's face and look over on the other side while holding it steady the ten cents side should be upside down. Often, counterfeiters forget this alignment issue. This test won't work on the one with George because the alignment is the same on both sides.
The value of these is low so there's not much reason to counterfeit them, but you never know!
Where did you get them if you don't mind sharing that info?

Porous surface on the first one.

I would agree with the other comments. I think the weak reeded edge and the porous surface indicate that the Victoria is not a mint cast coin, which wouldn't have the fuzzy details and crumbly look. In an original, you'd expect sharper details, even on a circulated coin. To me, the dull cull coloration suggests a non-silver metal or, if the coin is genuine, some kind of harsh cleaning that damaged the coin.
Please take a look at the "K" in Kong. It looks a bit odd!

Porous surface means the little holes and uneven surface you see.
The British colonial coins were minted to a high standard and you shouldn't see a porous surface.
Reeding is also clunky.

I got duped with a similar Hong Kong coin before so I'd know, a rare date 20 cents.

Brought it to a dealer and he pointed out the porous surface and "wrinkly" letters.

Lesson learned. Bought it from an elderly couple, doesn't look like they are getting rich of me, so just left it at that.

Who you buy from is as important as the details of the coin.

Kept the coin for future reference.

Thank you so much everyone for helping me out! :)

I'll be returning this coin to the dealer soon. I learnt a lot in this thread and hopefully, I won't make the same mistakes again. Also, I assume the Straits settlements silver is a genuine piece at least xD