You can't find a jade orb.
the jade orb allows you to get rayquaza
You have to get Groudon and Kyogre and go to Mr. Pokemon and he'll give you the Jade Orb.
In heart gold after catching Kyogre you will have the Blue orb. Get someone to trade you a groudon only then you can get the jade orb and catch raquazza
you get the jade orb by trading groudon to heart gold from soul silver and you have to show it to professor oak and he will give you the jade orb
you can't get it. trust me I've tried it. but you can get the red and jade orb. red for groudon jade for rayquaza
You'll need to have the Blue Orb and the Red Orb, take them to Mr. Pokemon and he'll give you a Jade Orb. Place the Jade Orb back to the Embedded Tower and then Rayquaza will appear.
To get the jade orb you need to beat all 16 gyms then go to mount silver and beat red. Then you have to get the red orb from mr Pokemon and after catching groudon you go to either mr Pokemon or prof. Oak and get jade orb
You get the orb once you show Professor Oak Groundon and Kyogre (You can get the other by trading from the other version. Then he gives you the Jade orb and you can catch Rayquazza in the embeded tower!
you cant
to find the jade orb you need grodon and kyouger so you need to trade from soulsliver to get grondon and catch kyouger in heart gold and then you need to go to profeser oak in pallet townand he will give you the jade orb
trade kyogre from heart gold our migrate form Sapphire or emerald. then show prof. oak kyrogre and he will give you the jade orb.
you need to trade groudon from soulsilver bring both of em to professer oak and he will give you the jade orb good luck on catching him >:(