Canned seafood products sometimes contain small crystals that look like glass. These crystals are quite large to be noticeable; and some consumers may even think that there is a foreign substance in their food. In fact, these fragments are harmless. These small crystals turn out to be fragments of a substance known as magnesium ammonium phosphate.
Magnesium ammonium phosphate is an inorganic compound, a complex salt of ammonium, magnesium metal and phosphoric acid with the formula NH4MgPO4, colorless crystals insoluble in water form crystalline hydrates.
Also known as “struvite“ – – (NH4) MgPO4 * 6H2O
| Molecular weight | 245.41 |
| Name origin | Was named after the German mineralogist and diplomat in the Russian service, Heinrich Antonovich Struve (Heinrich Christoph Gottfried von Struve, 1772-1851), who published “Works on mineralogy, mainly regarding Württemberg and the Black Forest” and “Mineralogy and Geology of North America”, Honorary Member of the St. Petersburg Academy of Sciences. |
| IMA status | Valid, described for the first time until 1959 (before IMA) |
| Opening year | 1846 |
Struvite is located in the deposits of guano, in peatlands rich in organic matter. Struvite as a biogenic mineral is often found in the decomposition products of organic compounds in a putrefactive environment, resulting from the action of bacteria on organic compounds, also known as an integral part of kidney stones and stones in the bladder and in the alkaline urine of infected people.
Physical properties
| Mineral color | colorless, white (dehydrated), yellow or brownish, light gray; colorless in internal reflexes and brightly. |
| Trait color | white |
| Transparency | transparent, translucent |
| Shine | glass |
| Cleavage | clear in {001}, perfect; according to {100}, very imperfect |
| Hardness (Mohs scale) | 1.5 – 2 |
| Kink | uneven, close to cancerous |
| Strength | fragile |
| Density (measured) | 1.711 g/cm3 |
| Density (estimated) | 1.705 g/cm3 |
| Radioactivity (GRapi) | 0 |
| Electrical properties of the mineral | Pyroelectric. Piezoelectric. |
Optical properties
| Type | biaxial (+) |
| Refractive indices | nα = 1.495 nβ = 1.496 nγ = 1.504 |
| 2V angle | measured: 37° , calculated: 40° |
| Maximum birefringence | δ = 0.009 |
| Optical relief | moderate |
| Optical axis dispersion | relatively weak |
Crystallographic properties
| Point group | mm2 – Pyramidal |
| Syngonia | Rhombic (orthorhombic) |
| Cell options | a = 6.94Å, b = 11.2Å, c = 6.13Å |
| Attitude | a:b:c = 0.62 : 1 : 0.547 |
| Unit cell volume | V 476.47 ų (calculated by unit cell parameters) |
| Twin | The acute poles of [001] unite in the composition plane {001}, with deep re-entrant angles. |
Not soluble in water.
Category: Health and Wellness
Tags: foods, nutrition