Can the formation of gypsum evaporites (sand roses) be simulated in the lab?
Yes, it has.

Cody &amp; Cody (1998), Journal of Sedimentary Research.

http://archives.datapages.com/data/sepm/journals/v55-58/data/058/058002/0247.htm

Abstract:


  Gypsum crystals were grown in experimental conditions analogous to
  saline terrestrial environments within bentonite clay gels by
  diffusion control at three different temperatures, four brine
  salinities, and four tannic acid (a model terrestrial humic substance)
  concentrations. The resulting crystals correspond to natural gypsum
  formed in terrestrial environments. Prismatic gypsum typically grew at
  both high and low temperatures in the absence of the organic additive.
  With increasing organic acid concentrations, the prismatic crystals
  progressively became flattened perpendicular to [001], and two
  temperature-dependent trends developed. At low temperatures, a
  hemi-bipyramidal habit dominated by 1111 faces developed, whereas the
  lenticular e103 dominated habit forme at higher temperatures. With
  progressively greater concentrations of organic material a(100)
  penetration twinning developed, secondary complex nucleation occurred
  near the twin interfaces, and finally, rosette and rosette-like
  aggregates formed. Higher temperatures generally favored better-formed
  and larger rosettes. The presence of 5% and 15% NaCl greatly decreased
  nucleation density and resulted in larger single crystals and crystal
  aggregates. The a(100) penetation twins appear to be diagnostic of
  gypsum growth in natural terrestrial sediments at a pH greater than
  7.5.


Relevant bit about gypsum roses is in bold.