If you would like specific information about the MicroMineral Symposium download this PDF. It's a four page informational flyer about the group meeting.
Sunday, April 13, 2025 Meeting
Presented by
Johan Maertens
1pm @ Eastside Branch
Lexington Public Library
This talk is about observations of frost crystals made over a one-year period (2011) at the speaker's home.
Ice is classified as a mineral if it is naturally occurring.
Frost, a variety of ice, forms when water vapor transitions to a solid, ice, without a liquid phase.
Many of the frost crystals in the presentation were ‘collected’ from north facing windows of his house.
The most common type of frost is irregular; however, window frost often forms hexagonal plates and columns.
The crystals are three dimensional and sometimes are seen as elaborate patterns.
Overall aggregate growth depends on the growth of each face, based on temperature, supersaturation levels, and one should also consider the type of surface (to which it is affixed).
Common habit changes occur at -4C, -10C, and -22C.
The speaker shows a wide array of detailed images, revealing the intricate patterns of frost crystals and polycrystalline aggregates.
The images include stellar or broad branched plates, perfectly hexagonal sectored plates with distinct ridges, and polycrystalline stellar dendrites.
Fernlike stellar dendrites occur when many side branches are formed.
Ice and frost are common minerals, yet minimally collectible?
Attached picture is copyrighted by Johan Maertens © and used by permission.
