Why a seamless pour has no joints and a tiled one has a grid, and where the divider goes.
1 questions in this harvest falls under this subject. 2 answered so far.
As narrow as the tiles allow — NTMA names one-sixteenth or one-eighth inch as the standard divider widths, and a wider joint interrupts the aggregate pattern and starts to read as a porcelain floor rather than a terrazzo one. Use a grout matched to the matrix, not a generic one.
Almost always because the substrate moved and the terrazzo moved with it. A cement-bound floor is ground together with the slab, so a crack in the slab is a crack in the finish at the same line. Joints are the answer, and their layout is a design decision taken before the floor exists.
Read the answer first — it says which of these to specify and why.
Ordered by how many questions each one holds.