Post: Post Reply: ? by Beadman

Original Message: ?

I am not following your train of thought.
Rosanna initially said she thought the bead(s) might be "some sort of soft stone or maybe grey coral." (Not cement.)
You suggest, "Clay has pozzolanic properties which allows it to cure when mixed with water into a strong cementitous product." However, the Wiki article says for pozzolana, "The major component is volcanic glass typically present in quantities over 50 wt%." So not a ceramic. And further says, "Zeolite, opal CT and clay minerals are often present in minor quantities as alteration products of the volcanic glass."
I have seen these beads. (Probably from Robert Liu's collection, a very long time ago.). But I have not paid much attention to them. My impression was that they were poorly-fired (still soft and friable) clay. They would not have the hardness and integrity of typical powderglass. However, I could not rule-out the possibility that they might be a crudely-made cement. I will ask Robert, the next time I speak with him, whether he has an opinion. JDA.
Copyright 2024
All rights reserved by Bead Collector Network and its users

Original Message: ?
I am not following your train of thought. Rosanna initially said she thought the bead(s) might be "some sort of soft stone or maybe grey coral." (Not cement.) You suggest, "Clay has pozzolanic properties which allows it to cure when mixed with water into a strong cementitous product." However, the Wiki article says for pozzolana, "The major component is volcanic glass typically present in quantities over 50 wt%." So not a ceramic. And further says, "Zeolite, opal CT and clay minerals are often present in minor quantities as alteration products of the volcanic glass." I have seen these beads. (Probably from Robert Liu's collection, a very long time ago.). But I have not paid much attention to them. My impression was that they were poorly-fired (still soft and friable) clay. They would not have the hardness and integrity of typical powderglass. However, I could not rule-out the possibility that they might be a crudely-made cement. I will ask Robert, the next time I speak with him, whether he has an opinion. JDA. Copyright 2024 All rights reserved by Bead Collector Network and its users

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