If Nephi had access to previous metals, why did he say his temple could not have so many precious things?

Biblical descriptions of Solomon’s temple suggest that “precious” things likely refer to the various kinds of stone and abundant gems available to Solomon and his people (Exodus 39:10-13; 1 Chronicles 29:2, 7-8; 2 Chronicles 3:6). Nephi’s temple was skillfully built after the general pattern of that earlier building and finely adorned, but not to the same degree.