Freezing and Thawing Cycle

[Darbi]

I have very stubborn matrices from Kiowa Formation that I am trying to break down to look for micro-fossils and fossil teeth. I have tried vinegar baths and ultrasonic cleaner to break it down quicker but it's not helping much. Anyway, I am trying the freezing and thawing cycles this time to further break it down. For the last few days, I had it soaked in water for about 24 hours and then I put it into the freezer bag to freeze it, and then thawed it out after overnight. Before freezing, should I add extra water into the bag or are the matrices being damp good enough? Are there more efficient ways to use the freezing and thawing cycle method? Thank you.

[connorp]

I am not familiar with this matrix, but having freeze-thawed other things, I would say that (1) depending on the size of the matrix pieces, 24 hours might not be long enough to penetrate deeply; (2) the matrix will dry out if not kept submerged when freezing

[Darbi]

On 5/29/2020 at 8:22 PM, connorp said:

I am not familiar with this matrix, but having freeze-thawed other things, I would say that (1) depending on the size of the matrix pieces, 24 hours might not be long enough to penetrate deeply; (2) the matrix will dry out if not kept submerged when freezing

Thank you! I did a week of daily freezing and thawing cycle and it worked pretty good.