Blessings of objects by the Priest Is there an official list of objects that must be blessed by a priest for a variety of purposes? 

General Example:  religious coins, saint necklaces, anniversary gifts given to or from someone etc.  

The Green Scapular for example must be blessed by a priest. And someone must say a particular prayer daily. This is an example of an religious object a priest must bless.
There is no list of items that &quot;must&quot; be blest by a priest (or a deacon), yet we Catholics are used to blessing everything.  There are items that can be required to be blest by a certain person.  The crucifix of St. Benedict is required to be blest by a deacon or priest.  There really isn't a source of which I am aware one can go to to find this kind of answer, but the catechism addresses it more in terms of general principles.  See CCC Chapter 4, Article 1, paragraphs 1667-1679.
In terms of blessing sacramentals, this is the general principle from the catechism:

Sacramentals derive from the baptismal priesthood: every baptized person is called to be a “blessing,” and to bless. [Cf. Gen 12:2; Lk 6:28; Rom 12:14; 1 Pet 3:9.] Hence lay people may preside at certain blessings; the more a blessing concerns ecclesial and sacramental life, the more is its administration reserved to the ordained ministry (bishops, priests, or deacons). [Cf. SC 79; CIC, can. 1168; De Ben 16, 18.]
CCC 1669

Further, Canon Law states:

The minister of the sacramentals is a cleric who has the requisite power. In accordance with the liturgical books and subject to the judgment of the local Ordinary, certain sacramentals can also be administered by lay people who possess the appropriate qualities.
Canon 1168

The forms of sacramentals described in 1670 is expressed this way, &quot;Among sacramentals blessings (of persons, meals, objects, and places) come first.&quot;
From this it is clear that liturgical and sacramental blessings require a deacon or priest.  It also implies ordinary Christians can bless outside sacramental and ecclesial (church) life (except in the case of solemn or major exorcism, see 1673).  It would be advisable for a Catholic to consult the parish priest or diocesan bishop concerning this to avoid dangers or going too far with it.