The cement, concrete, and cinder block labels have certainly been
blurred in common usage, although I think it is important to recognize
both the correct technical meanings as well as the common, blurred
usages which do have a cultural validity.  As with 'kleenex' often being
used to refer to any brand of facial tissue, 'cinder block' seems to
have been used for several decades to designate any concrete block
regardless of the presence of cinders.  It may be technically incorrect
but if so used has become part of the contemporary lexicon.  The
'Cindercrete' trademark with which I am familiar is a case in point: the
creation of a hybrid manufacturing term which well may have/have had no
direct association with cinders as part of the concrete recipe.

In regard to my original posting on this thread, Ron May made a good
point that concrete block usage did continue into the 1920s in domestic
dwelling architecture, via stucco-on-block, 'mock adobe'.  He cited the
1925 World's Fair as the origin of this style.  I've seen many examples
of this, often with a relatively flat roof in a Spanish or Southwestern
theme, such as a combination with ceramic roof tiles, mock extending
roof lintels, wrought-iron-decorated Spanish balconies, various alcoves,
extending front-yard exterior seating areas, etc.  It seems that the
medium of concrete block was well suited, if not better suited, for this
architectural trend (mock adobe) than perhaps earlier usages where it
was a replacement for conventional masonry (mock stone).

Of course, burnt clay tile blocks were also used widely in the pre-WWII
period as a structural base for either stucco or facebrick, and as the
dimensions could be identical to concrete blocks, a resulting structure
built with these would appear identical to one built from concrete
blocks.  It seems that burnt clay tile blocks were rarely used as an
exterior face in themselves, with examples I've seen being rear or
side-walls of commercial or industrial structures.  Another good reason
to tour back lanes and alleys.

The architectural trend of stucco-on-block seems to have continued in
perhaps a low but stable frequency through the 1930s and possibly as
late as the 1950s, if the incorporation of hollow glass block in later
examples is any indication.  Does anyone know when hollow glass block
first became popular?  I've seen both buildings where glass block seems
to have been originally incorporated as well as earlier (including late
Victorian) examples where it was deliberately added at a much later
date.

Larry Buhr
University of Nevada, Reno