Sieving samples before initial etching:

Sieve samples to an appropriate size for mineral separates approximately 800-500 microns and 500-250 microns. Grains of these size fractions are mostly monomineralic

1 Set up two sieve sets with 2 very coarse top sieves, an 800 to 850 micron sieve, a 500 micron sieve, a 250-200 micron sieve, and a tray at the bottom. make sure all sieves have been wire brushed. Running two sets of sieves will let you clean one while the other set is shaking.

2. Pour sample into 800 micron sieve and set on ROTAP shaker. Set timer to run sieve shaker for 2-3 minutes minimum.

3. Remove sieves from shaker and disassemble stack carefully. Have labeled set of bags ready. Bag and save >800 micron material. Separately bag and save 800-500 micron material. Separately bag and save 500-250 micron material. Discard <250 micron material. Place all bags for one sample in a large "MASTER" bag, label and set aside.

4. Clean sieves carefully between samples using stiff wire brush. Sweep sample table between each sieving. Only a few sample grains should remain lodged in each sieve.

5. Place completed samples in locked drawers. Label drawers.