Many minerals may be found as inclusions in natural crystal quartz. It is coming from the class of framework silicates. Natural crystal quartz with inclusions has trigonal crystal system and composed from silicon dioxide. Technically, an inclusion is material that is different from the chief elements of the host, found within the body of a crystal.
Tourmaline, chlorite, ajoite, papagoite, hematite, limonite, kaolinite, hydrocarbons, and rutile are just some of the materials that occur as inclusions in natural crystal quartz, and each produces a different effect. Clear prisms of natural crystal quartz that reveal attractive displays of the inclusions they host are known as “scenic” or “garden” quartz. The colors available are colorless with inclusions, blue, black, gray, yellow, green, gold.
When cut en cabochon, natural crystal quartz containing inclusions may show a chatoyant (cat’s eye) effect, this cutting style can also magnify the inclusions. Its habit is striated hexagonal prisms with sets of positive and negative pyramidal terminations. Natural crystal quartz with inclusions has refractive index between 1.544-1.553 and the birefringence is 0.009. The main sources of this exotic natural gemstone are Germany, Sri Lanka, USA, Madagascar, Switzerland, Brazil, India, and South Africa. This kind of quartz has rhombohedral cleavage that rarely seen. The luster is vitreous and the fracture is conchoidal to uneven.
Brilliant and step cuts, and beads are also used. a rutile/hematite starburst is probably the most sought-after type of natural crystal quartz with inclusions. This gemstone has a 0.013 dispersion and specific gravity about 2.65. Phantoms, “starburst,” “flowers,” “snowflakes,” and dendrite are valuable and in great demand with collectors. The value is related to the rarity, distinctiveness, and beauty of the inclusions, the more centrally placed and less obscured it is, the higher the value.
The most popular natural crystal quartz with inclusions is rutilated natural crystal quartz (or sagenite). It is transparent rock crystal with golden, silvery, or red needles of rutile displayed in patterns within it. Each pattern is different and some are extraordinarily beautiful. The inclusions are sometimes called Venus hair or Cupid’s darts. Less well known is a variety called tourmalinated quartz which, instead of rutile, has black or dark green tourmaline crystals contained within it. The hardness of natural crystal quartz with Inclusions is stopped at level 7.
Opaque, metallic inclusions of gold and silver are also possible, as well as branchlike, silvery, gray, or black dendrites of manganese and iron oxides. Even gas bubbles can make impressive natural crystal quartz inclusions.
