This specimen hosts two superb, elongated, very well formed crystals to 7 cm of the rare aragonite varietal termed nicholsonite. The yellow color is due to high nickel content. This is not a valid species anymore, but is a valid subtype of aragonite, rich in both nickel and lead (tarnowitzite, has just the lead part). I have not seen a more aesthetic example of this rare material for sale! images/cards.gif images/bottom.gif