The Position Of The Church
The Orthodox Church does not accept any and superstitions, including those relating to the crucifix. All views about the "deterioration", "hex", "transfer of doom" absurd from the point of view of a Christian: the fate of a person disposes of God, and the Holy symbol cannot carry any "negative energy", whose existence, moreover, is not proven.
For the Christian, crucifix, donated by anyone – not the mythical source of danger, and precious gift, full of deep spiritual meaning associated with a wish for God's blessing. Especially valuable gift would be a crucifix, sanctified in any Holy place. To accept such a precious gift, of course, can and should be.
If a person who received a cross as a gift, already have a crucifix, he can wear both cross at the same time, one by one, or keep one of them next to the icons, and the other to wear – none of these options the Church is not prohibited.
Ticklish situation takes place only in case, if an Orthodox Christian received the gift of a Catholic cross. Make the gift you need, because it is dictated by love, but to wear such a cross should not be.
Crucifix and twinning
A special situation occurs when two people give each other their crosses. Not so long ago, in the early 20th century, this action makes people "cross brothers" or sisters.
The custom of fraternization existed in pre-Christian times pagan bro, mixing blood or exchanging weapons. In the Christian era, the conclusion of twinning was associated with a crucifix, a sacred object, closely associated with faith and soul. This "spiritual kinship" seemed even more sacred than the blood relationship.
In the modern world the tradition of brotherhood through an exchange of crucifix almost forgotten, but nothing prevents modern Orthodox Christians to revive it.