There are many spiritual gifts. It is easy to find lists that include twenty or more spiritual gifts. Some seem to be almost common and natural but generally a gift is a spiritual gift if it is firstly above average and secondly if it has a spiritual purpose.
On the other hand, every good gift comes from God. So, every skill, talent or ability can be a spiritual gift. A gift is a spiritual gift if it is used to further the purposes of God. A person may be a spiritual gift to another person or a group. The Holy Spirit might give a Apostle or Pastor to a congregation, for example. The use and holy purpose of a gift make it a spiritual gift.
What SDAs Believe About Spiritual Gifts and Ministries
19 Spiritual Gifts Defined (Spiritual Gifts Test)
Spiritual Gifts (Alli Patterson)
29 Spiritual Gifts (Larry Tomczak)