Tool for Microscopic Identification Home

 

Organics

Id Identification Type Name Description Distinguishing Features Tags
57 Algae Algae
137 Algae Algal organic matter
87 Arthropod Arthropod
127 Invertebrate Bivalve
141 Invertebrate Bryozoa
160 Plant Carbonized Organic Matter
78 Plant Charcoal
100 Algae Charophyte Multicellular charophyte algae such as _Chara_ form calcium carbonate (calcite) encrustations on their surfaces. Transparent colorless to murky or stained with black. Nonpleochroic. High birefringence (small irregular calcite crystals). Irregular shapes include tubes and nodules. Moderate relief. _Chara_ is typically found in calcium-bicarbonate waters; other genera are found in fresher water. bumpy
high-birefringence
Carbonate
transparent
colorless
125 Arthropod Chironomid shell
carapace
brown
amber
insect
161 Invertebrate Chitin
128 Algae Chlorophyte
122 Algae Chrysophyte
126 Arthropod Cladocera
63 Algae Coccolithophore
77 Arthropod Crustacean
93 Algae Cyanobacteria When preserved, cyanobacterial remains have a characteristic blue-green pigment. Filaments may or may not be visible. Occur in zones of rapid deposition and anoxia, sometimes associated with diagenetic minerals also formed in reducing environments. Likeliest to be found in very recent sediments, as oxidation of pigments occurs rapidly. Blue-green
Filamentous
101 Arthropod Daphnia
129 Algae Desmids
79 Algae Diatom Transparent colorless to slightly brown or red tinted. Nonpleochroic. Isotropic. Many different shapes; in two-dimensional view these may appear as circles, rectangles of varying aspect ratios, canoe-shapes, banana-shapes, etc. moderate relief. Occur in essentially all lakes and rivers, but may not be preserved in sediments due to high- or low-pH conditions or silica undersaturation of bottom waters. Isotropic
Patterned
circular
transparent
colorless
rice-shape
89 Arthropod Ephydra
81 Fish Fish
64 Invertebrate Foraminifera
83 Invertebrate Gastropod
80 Arthropod Insect
140 Plant Mycorrhizae
92 Arthropod Ostracode
94 Algae Phacotus Transparent colorless spheres show white and occasionally pastel birefringence colors. A dark ragged "X" across the sphere (also described as a pinwheel, baseball seams) rotates as the stage is rotated. Phacotus is a lacustrine green alga with a calcite lorica, and can be abundant in temperate hardwater lakes. Lorica with two slightly different appearances in cross-polarized light (one sometimes with a red ring near the perimeter) may be views of the outside and inside of loricae, as they commonly separate after death. Circular
Moderate-birefringence
Pinwheel-extinction
carbonate
lorica
99 Plant Phytolith Phytoliths are literally “plant stones”, and can include deposits of amorphous silica or calcium oxylate. For purposes of this site, we will be considering deposits of amorphous silica, deposited as secondary cell walls within plants. Grasses are the source of most of the phytoliths found on smear slides, however sedges, cattails, and horsetail are also prolific producers of phytoliths. The cell walls are three-dimensional bodies, only two of which are easily seen in bright field microscopy. Phytoliths will appear as transparent to translucent isotropic shapes, including circular, oval, cylindrical, dendritic, rectangular, triangular, or lobed.

Phytoliths, like other solid amorphous silica components, can appear purplish in plane polarized light. Nonpleochroic, isotropic. Moderate relief.
Isotropic
Transparent
colorless
purplish
dendritic
circular
triangular
lobed
82 Plant Plant
136 Plant Plant Macrofossil
96 Plant Pollen
75 Invertebrate Radiolarian
66 Algae Silicoflagellate
84 Invertebrate Sponge Transparent colorless. Moderately high relief. Isotropic. Sponge spicules (amorphous silica structural elements) are most often large (~0.1 to >1 mm), needle-like, gently curved, sometimes with a medial groove or tube. Ends may be pointed or rounded. Surface is frequently smooth and unornamented, but may be covered with prominent bumps. Distinguished from diatoms by size, lack of ornamentation, robustness/solidness. Marine forms may be more complex, tri- or tetraxial. Marine forms may less commonly be calcareous instead of siliceous. Acicular
Needle-like
Curved
Isotropic
Large
spicule
groove
bumpy
162 Plant Thick Plant Matter