Dietary mineral

Dietary minerals are the chemical elements required by living organisms, other than the four elements carbon, hydrogen, nitrogen, and oxygen present in common organic molecules. The term “mineral” is archaic, since the intent of the definition is to describe ions, not chemical compounds or actual minerals.

Dietitians may recommend that minerals are best supplied by ingesting specific foods rich with the element(s) of interest. Sometimes minerals are ingested as mineral dietary supplements, the most common being iodine in iodized salt.

The dietary focus on minerals derives from an interest in supporting biochemical reactions with the required elemental components. Appropriate intake levels of certain chemical elements are thus required to maintain optimal health. According to nutritional experts, the requirements are met simply with a conventional balanced diet.

Some sources state that sixteen minerals are required to support human biochemical processes by serving structural and functional roles as well as electrolytes: The term “dietary minerals” does not include the fundamental elements of organic chemistry: hydrogen, carbon, nitrogen, and oxygen. Also, sometimes a distinction is drawn between this category and micronutrients. Most of the essential minerals are of relatively low atomic weight:

Powder Color

The streak (also called powder color) of a mineral is the color of the powder produced when it is dragged across an unweathered surface. Unlike the apparent color of a mineral, which for most minerals can vary considerably, the trail of finely ground powder generally has a more consistent characteristic color, and is thus an important diagnostic tool in mineral identification. If no streak seems to be made, the mineral’s streak is said to be white or colorless. Streak is particularly important as a diagnostic for opaque and colored materials. It is less useful for silicate minerals, most of which have a white streak and are too hard to powder easily.

The apparent color can vary widely because of trace impurities or a disturbed macroscopic crystal structure. Small amounts of an impurity that strongly absorbs a particular wavelength can radically change the wavelengths of light that are reflected by the specimen, and thus change the apparent color. However, when the specimen is dragged to produce a streak, it is broken into randomly oriented microscopic crystals, and small impurities do not greatly affect the absorption of light.

The surface across which the mineral is dragged is called a “streak plate,” and is generally made of unglazed porcelain tile. In the absence of a streak plate, the unglazed underside of a porcelain bowl or vase or the back of a glazed tile will work. Sometimes a streak is more easily or accurately described by comparing it with the “streak” made by another streak plate.

Because the trail left behind results from the mineral being crushed into powder, a streak can only be made of minerals softer than the streak plate, around 7 on the Mohs scale of mineral hardness. In this case, the color of the powder can be determined by filing or crushing with a hammer a small sample, which is then usually rubbed on a streak plate. Most minerals that are harder have an unhelpful white streak.

Some minerals leave a streak similar to their natural color, such as cinnabar and azurite. Other minerals leave surprising colors, such as fluorite, which always has a white streak, although it can appear in purple, blue, yellow, or green crystals. Hematite, which is black in appearance, leaves a red streak which accounts for its name, which comes from the Greek word “haima,” meaning “blood.” Galena, which can be similar in appearance to hematite, is easily distinguished by its gray streak.

Mineral ascorbates

Mineral ascorbates are salts of ascorbic acid (aka vitamin C). They are powders manufactured by reacting ascorbic acid with mineral carbonates in aqueous solutions, venting the carbon dioxide, drying the reaction product, and then milling the dried product to the desired particle size.

The choice of the mineral carbonates can be calcium carbonate, potassium carbonate, sodium bicarbonate, magnesium carbonate, or many other mineral forms. Ascorbates are highly reactive antioxidants used as food preservatives.

Ascorbate salts may be better tolerated than the corresponding weakly acidic ascorbic acid.

Examples of mineral ascorbates are:

• Sodium ascorbate (E301)
• Calcium ascorbate (E302)
• Potassium ascorbate (E303)
• Magnesium ascorbate

A study found ascorbates (as magnesium or calcium ascorbate) to be a very effective chelator of aluminium, especially when the aluminium was bound to brain cell DNA. Taking higher doses of ascorbate with magnesium citramate increased the removal of aluminium.

Ascorbic acid is a sugar acid with antioxidant properties. Its appearance is white to light-yellow crystals or powder, and it is water-soluble. One form of ascorbic acid is commonly known as vitamin C. The name is derived from a- (meaning no) and scorbuticus (scurvy), the disease caused by a deficiency of vitamin C. In 1937 the Nobel Prize for chemistry was awarded to Walter Haworth for his work in determining the structure of ascorbic acid (shared with Paul Karrer, who received his award for work on vitamins), and the prize for Physiology or Medicine that year went to Albert Szent-Györgyi for his studies of the biological functions of L-ascorbic acid. At the time of its discovery in the 1920s, it was called hexuronic acid by some researchers.