An excellent routine for children’s entertainers, conceived by Ian Adair,  the props for this comprise of a cut out crown with a large jewel, and a safe. 
In the routine suggested by Ian, the crown is at first covered with a cloth or opaque silk. The performer states that the Queen owns a very valuable crown and in it’s center is a priceless jewel. He further states that when the Queen is not wearing her crown she asks for the priceless jewel to be removed and placed inside the special security safe. He opens, first the first door … it’s not there. He opens the second door and points as if it is there, but it isn’t. The priceless jewel has gone missing. Then he uncovers the crown to show that the jewel is there, set in the center of the crown. He removes the jewel, pokes his fingers through the big gap and recovers the crown.
He places the jewel inside one of the compartments of the two-doored case (safe !) closing the door. Here the usual tipping from one side to the other takes place … ( ala the Die Box) the jewel has gone. Perhaps someone has stolen it. Each door, one at a time being opened for the fun, then both … It Has Gone! Where can it be ?
He rushes over to the silk covered crown, whips the silk off … but it is not there. He covers it again, , gets the children to shout out the magic words etc. and yes … when revealed, its back in position, set in the center of the crown. (It is not necessary to cover it, you can have the Jewel re-appear visibly if you prefer.)
We have produced the props in durable wood, painted and screened in bright colors, to bring you a quality model of a novel and new routine which children’s performers will love. This is a compact model, which will fit into a brief case, yet make a big eye-catching display. The crown measures 10.5″ in length, and 6″ high, with the jewel 2.25″ in diameter. It plugs/unplugs instantly into the base (8.25″ x 5″) allowing you to set this up or dismantle this in seconds. The “safe” is 6″ long, 3″ high, and 1.75″ deep.
These are two complete different effects – The Crown which works like Forgetful Freddie, (you can eliminate the safe and vanish the jewel in a change bag if you prefer), and the safe (like the die box, which you could use with a Jumbo Coin as a different trick). Together they combine into a perfect routine. Supplied complete with all required props, and instructions.

Adairs Crown Jewel-Compact Size