Absolutely! You’re in luck, there are many of great object spells out there 
To help narrow it down, I guess I should ask first if you want to consecrate it (preparing a tool or object for magickal use or workings), cleanse it (cleaning it of any old, negative, or stagnant energy), or enchant it (imbuing an object with certain magickal qualities- such as for luck, love, money, etc).
All of the above options are similar, but will have differing effects on the object.
Here are a few spells for each that you might consider:
Consecration:
Cleansing : ( this spell is perfect for this weekend’s Full Snow Moon! 
)
Enchanting :
There’s also a general blessing spell that can be used on objects:
And you may find some more ideas from the entries the coven shared in the previous Making Objects Magickal Challenge- everyone shared some great examples of casting magick on objects, for various intentions and purposes! 
Making Objects Magickal Challenge
I hope you’re able to find the perfect spell for blessing your necklace- may it carry your intention and help you in positive ways!
Good luck and blessed be 
