Some of the crystals are inside icicles. To get them you must use the 'flipendo' spell. Those that are inside carts you can get by using the B button.
Hint: Alohomora spell
In order to get the last spell, Alohomora, you must get all five Famous Witches And Wizards "Charms" cards in your collection.
Hint: Bestiary option
Complete the five Famous Witches and Wizards cards "Creatures" in your collection. After you collected all five, there will be a new category in your menu which will give information about the creatures you will commonly see in the game.
Hint: Charms cards
The following cards are referred to from left to right.
First card: Found during your Leviosa Challenge.
Second card: Secret room in portrait hall.
Third card: Room in Flitwick's office.
Fourth card: Secret room, corner of Gryffindor common room where you light torches with incendio to open a wall.
Fifth card: Bonus room in portrait hall, with male portrait.
Hint: Defeating Peeves
When facing Peeves in Restricted section of the library, use a full force Flipendo spell on him first to make him hide in armor suits. When he hides, immediately use a full force Flipendo spell on the armor suit where he hides. It will be destroyed. Be careful, as it sometimes gives off Dungbombs which costs 3 points of life. Repeat the steps, as there are four armor suits. When all are destroyed, use a full force Flipendo spell again on Peeves until he gives up.
Hint: Defeating The Basilisk
Have the selected spell as Inciendio. This should do more damage than Flipendo. When you enter the chamber, Fawks should "take" his eyes, making him blind. When he goes in a circle, continuously cast Inciendio. Make sure he does not touch you, or you will be poisoned. Watch out when he makes rocks come down and dodge his spit. This may take awhile, but you will eventually defeat him.
Hint: Floo Powder
When in the leaky cauldron, go into the room by the furnace and pull the lever found in the room. Then, go out of the room. Go to the west side of the store. Pull the lever and the bookcase will open. Go inside the room and open the chest. You will obtain the Floo Powder. Take it to Ron and you will go to Hogwarts.
Hint: Gemstones to open the door
Gemstone 1: In the first chest box near the slugs.
Gemstone 2: Defeat all three Fire Turtles.
Gemstone 3: In the box next to the switch that activates the crushers.
Gemstone 4: In gem cart near were the mine carrying cart that takes you out is located.
Gemstone 5: In boulder. To get out, turn on crusher, put the boulder under it, and turn the crusher switch.
Hint: Girding Potions
Complete the five Famous Witches and Wizards card "Potions", and you will receive five Girding potions.
Hint: Increase your boost bar
When at the flying lessons press A at the start when the countdown reaches "1". Note: Timing is critical.
Hint: Skurge spell
Defeat Peeves the first time you enter the Restricted section of the library on the second floor.
How to get alohamora
Get all 25 wizard cards.
How to Trade And Get Best Armor
You start in diagon alley in the quidditch shop. Buy Chudley-cannon's shirt. You must give it to Ron when you have bought it. He will give you a baseball card. Give it to the boy in the card shop. He gives you a wrongly printed card. Give it to the painter on the 6th floor in Hogwarts. The painter gives you a little spider. Give it to Hagrid. He gives you a necklace. Give it to Filch and he will give you a lockhart photo. Give it to the girl on the 3rd floor. She will give you a flashlight. Give it to the boy in the classroom on the 5th floor. He will give you a mouth organ. Give it to the boy in the music classroom. He will give you a whistle. Give it to the proffesor. He will give you the best armor in the game.
Jump Spell
This really isn't a useful cheat, but it's fun to do it. First, you must have at least one spell(Duh!). If you have more than one spell, pick one, then do this: press R and A at the same time. When you jump into the air by pressing R, you should be in the spell-casting position. The spell should fire as soon as you hit the ground.
Unic card
Go to the library right next to Madam Pince and press A on the bookcase and you will find a unic card.