We see Calcite in a variety of colors, but rarely as a rich burnt orange like this - so it is good and unique from ANY locality but also happens to be from an old vacation spot! This is from a very famous area but an obscure mineral locality in Baja California that isn't even represented on mindat. An earlier generation of drusy, ivory colored Calcite is seen on the right side of the piece; and the remainder of the piece has translucent to nearly transparent, burnt orange rhombs from 0.5 to 2.5 cm on edge clustered on the earlier Calcite and the gray limestone matrix. The largest Calcite crystal is perched atop the piece and shows off its rich color and transparency along with its almost waxy luster. There is an adjacent rhomb that is very unusual in that it is half burnt orange and half colorless and nearly transparent! The clear portion looks as if it is later overgrowth. Ex. Miguel Romero collection, later in the collection of Dr. Peter Megaw - so we have provenance from literally the two most important Mexican collectors of the last 50 years. .