£2.00 – £8.00
Puddingstone conglomerate is a rare sedimentary rock from Hertfordshire, UK which formed during the Paleocene to Eocene period. Composed of rounded flint clasts within a silica matrix, this rock is quite hard and breaks with conchoidal fractures. Formed through erosion of flint pebbles which were later cemented by sand and silica, it is an excellent representation of conglomerate, detailing rounded clasts within a matrix. The specimens are available in 4 sizes and come supplied in a card tray with a label.
Puddingstone is a variety of conglomerate found in Hertfordshire, UK which formed during the Paleocene to Eocene period around 56 millions years ago. A sedimentary rock, these specimens are excellent examples of conglomerate, detailing textbook features such as a fine matrix with well rounded clasts. This particular rock is composed almost entirely of silica and has no porosity, likely resulting in its notorious hard state. It is theorised that this puddingstone began formation during the early Paleocene when rapid erosion of chalk beds occurred leading to a huge amount of flint being deposited into the proto-North Sea. Over the years, wave action resulted in the flint becoming smooth and rounded, almost ovoid in shape and deposited during the late Paleocene 56 million years ago as shingle/cobble beaches. As percolation of silica-rich water began just below the ground, sand began to be deposited between the flint pebbles holding them in place, the sand later was also infilled by crystalline silica to make a nearly pure silicate rock with a hard form. Due to this, puddingstone is different among conglomerates as it formed through wave action and percolation of ground water as opposed to erosion and cementing through material carried by a river. Due to the silica rich nature of the rock, puddingstone conglomerate has a natural shine to it, as if it has been polished and care should be taken when handled as specimens may contain sharp edges. This rare rock is only found in quantity at one locality in Hertfordshire and as such is becoming exceedingly hard to obtain. We can supply this rock in 4 sizes and each piece will come supplied in a card tray with a label.