The core promoter region is located most proximally and contains the RNA polymerase binding site, TATA box, and transcription start site (TSS). RNA polymerase will bind to this core promoter region stably and transcription of the template strand can initiate. The TATA box is a DNA sequence (5'-TATAAA-3) within the core promoter region where general transcription factor proteins and histones can bind.
The color palette of diamond is very richly varied; it ranges from pink through red, blue, green, yellow and brown even to black diamonds. The rarest color occurring in natural diamonds is red, followed by green, blue, purple and brown.
Alexandrite, a strongly pleochroic (trichroic) gem, will exhibit emerald green, red and orange-yellow colors depending on viewing direction in partially polarised light. However, its most distinctive property is that it also changes color in artificial (tungsten/halogen) light compared to daylight.tones that show a dramatic color change and strong colors (e.g. red-to-green) are rare and sought-after, but stones that show less distinct colors (e.g. yellowish green changing to brownish yellow) may also be considered alexandrite by gem labs such as the Gemological Institute of America.