# Hiddenite - Page: https://taslar.bumba.tr/en/stones/hiddenite/ - Turkish: Hiddenit - Also known as: Lithia emerald (historical) - Kind: Variety - Classification: Minerals › Silicates › Inosilicates - Chemical formula: LiAlSi₂O₆ - Crystal system: Monoclinic - Hardness (Mohs): 6.5–7 - Specific gravity: 3.03–3.23 g/cm³ - Refractive index: 1.66–1.68 - Lustre: Vitreous (glassy), Pearly - Transparency: Transparent, Translucent - Colours: pale green, yellowish green, green, emerald green, bluish green - Streak: White - Cleavage: Perfect in two directions on {110}, at about 87° - Fracture: Uneven to subconchoidal - Value ladder: 6/9 step, Fine ornamental and collector stone The pale to emerald-green variety of spodumene: found in North Carolina in 1879, it later gave its name to the town where it was found. Hiddenite is the green variety of spodumene, a lithium-bearing mineral, and owes its vivid green to traces of chromium. It was first found in 1879 in the US state of North Carolina and is named after William Earl Hidden, the geologist who brought the find to light. It is the sister of pink kunzite. Chromium-coloured hiddenite from North Carolina is very rare; green spodumene also comes from Brazil, Afghanistan, Madagascar and China, but how much of it counts as true hiddenite is debated. ## How does it form? Hiddenite, like the other [spodumene](/en/stones/spodumene/) varieties, forms in pegmatites: a pegmatite is a coarse-grained rock that crystallises slowly from the last, water-rich part of a magma. At the North Carolina deposit, as S. C. Davidson of Harvard described in 1927, thin quartz–feldspar pegmatite veins cut a fine-grained, intensely folded gneiss. The hiddenite crystals grow in cavities (druses) in these veins together with quartz, feldspar, pink garnet, mica and calcite. The green colour comes from traces of chromium built into the spodumene crystal structure; at other deposits iron can also give yellowish green tones. ## What is it used for? - **Jewellery:** Clear, vivid green crystals are cut as gems for rings, pendants and earrings. Its two cleavages and splintery fracture make it hard to cut, and it needs care in jewellery exposed to knocks. - **Collecting:** Chromium-coloured hiddenite from North Carolina is very rare and increasingly hard to obtain; raw crystals are kept in museums and collections. - **Scientific interest:** The cause of the colour of green spodumene from Afghanistan and Pakistan is still a matter of debate among gemmologists. ## Discovery and name Around 1879 a man named Lackey found the first green crystals near the settlement of White Plains in Alexander County. The local merchant J. A. D. Stephenson showed them to William Earl Hidden, who was searching the area for platinum on behalf of Thomas Edison. Hidden sent samples to the Louisville chemist J. Lawrence Smith, who identified them as spodumene and named the gem “hiddenite” in Hidden's honour. Hidden bought the land and set up a mining company; the diggers first took crystals from the clay and then, after reaching bedrock at about 8 metres, straight from the solid rock. In those years the gem was also called “lithia emerald”. ## Does its colour fade? Like kunzite, hiddenite can fade after long exposure to bright light and sunlight. Spodumene turned green by irradiation loses its colour in light much faster. That is why hiddenite jewellery should not be left in the sun, and should be cleaned with warm soapy water rather than in ultrasonic or steam cleaners. ## How to recognise it - It is strongly pleochroic: viewed from different directions, its green looks paler or deeper. - Its hardness is 6.5–7, but it has two perfect cleavages and a splintery fracture, so a hard knock easily splits or chips it. - Its refractive index is about 1.66–1.68 and its specific gravity about 3.1–3.2; these values help to tell it from emerald and green tourmaline. - Emerald, green tourmaline and green garnet are usually a deeper green and harder; peridot, which is more yellowish, is easily confused with hiddenite. A gem laboratory is needed for a certain identification. ## Fakes and imitations - Irradiated green spodumene: pale spodumene can be turned green by irradiation; this artificial green fades quickly in light and is hard to tell from the natural stone. - Peridot, green tourmaline and other green stones can be mistaken for hiddenite or offered under its name. ## What determines its value? Colour matters most for hiddenite: a vivid, saturated emerald green caused by chromium is the most sought after, while pale and yellowish green stones are often counted simply as “green spodumene”. Stones from North Carolina are so rare that origin adds greatly to value. Stones turned green by irradiation, which may fade in light, are worth less, so a laboratory report documenting treatment and origin matters. Because of its two cleavages, the quality of the cut and undamaged edges also count. This information is educational, not buying, selling or investment advice. Value varies enormously with quality and treatment. ## Myths and misconceptions - Myth: Hiddenite is a kind of emerald; that is why it was once called “lithia emerald”. Fact: Hiddenite is the green variety of spodumene, while emerald is a variety of beryl. The name “lithia emerald”, used in the 1880s and 1890s, referred only to its colour; the two are different minerals. - Myth: Every green spodumene is hiddenite. Fact: The name belongs to green spodumene coloured by chromium. Pale yellowish green stones coloured by iron, and stones turned green by irradiation that fade in light, are in most experts' view green spodumene rather than hiddenite. - Myth: Hiddenite is named after the town of Hiddenite in North Carolina. Fact: It is the other way round: the gem was named in 1879 in honour of the geologist William Earl Hidden. The settlement of White Plains later took the gem's name and became Hiddenite. ## What is it believed to be good for? This section reports beliefs; it is not health information. There is no scientific evidence for these claims and no stone replaces medical treatment. - Today crystal-therapy websites and stone sellers claim that hiddenite is linked to the heart chakra, eases fear, increases compassion and love, and brings comfort under emotional stress. What science says: There is no scientific evidence that hiddenite affects emotions or eases stress. Because the stone was only recognised in 1879, these beliefs come not from an old tradition but from recent crystal-therapy thinking; its green colour is due to traces of chromium in the crystal. ## Did you know? - William Earl Hidden had been sent to North Carolina by Thomas Edison to look for platinum; he found none, but he brought this green gem to light. - The settlement where the gem was found was called White Plains; it later took the gem's name and became Hiddenite. - In 1892 the mineralogist George F. Kunz wrote that the finest hiddenite crystal found so far was 68 mm tall and could have yielded a cut stone of about 5.5 carats. ## Where is it found? - Hiddenite (formerly White Plains), Alexander County, North Carolina, USA (Type locality): Hiddenite was found here, west of Stony Point, in 1879; the settlement later took the gem's name. The crystals grow in cavities in thin pegmatite veins cutting gneiss - Urucum mine, Galiléia, Minas Gerais, Brazil (Known locality): A granite pegmatite in the Aimorés pegmatite district; its output of hiddenite is small and sporadic - Kunar Valley, Afghanistan (Known locality): Whether the green spodumene of Afghanistan and Pakistan counts as hiddenite, and whether its colour comes from irradiation, is debated - Madagascar (Known locality): One of the countries where hiddenite has been found in recent decades; shown at country level because the sources name no deposit - China (Known locality): Wikipedia lists China among the countries where hiddenite has been found; shown at country level because no deposit is named ## Sources - [Hiddenite](https://en.wikipedia.org/wiki/Hiddenite), Wikipedia - [Hiddenite, North Carolina](https://en.wikipedia.org/wiki/Hiddenite,_North_Carolina), Wikipedia - [Hiddenite in North Carolina (S. C. Davidson), American Mineralogist 12](https://msaweb.org/AmMin/AM12/AM12_305.pdf), Mineralogical Society of America, 1927 - [Handbook of Mineralogy: Spodumene](https://www.handbookofmineralogy.org/pdfs/spodumene.pdf), Mineralogical Society of America - [The Gemstone Hiddenite](https://www.minerals.net/gemstone/hiddenite), Minerals.net - [Hiddenite, the green color variety of the mineral spodumene](https://galleries.com/minerals/gemstone/hiddenit/hiddenit.htm), Amethyst Galleries (galleries.com) - [Hiddenite (Jewelry Encyclopedia)](https://langantiques.com/university/Hiddenite), Lang Antiques - [Brazilian Hiddenite (Urucum mine)](https://www.gemadventurer.com/?p=2370), Gem Adventurer - [Galiléia](https://en.wikipedia.org/wiki/Galil%C3%A9ia), Wikipedia - [Kunar Province](https://en.wikipedia.org/wiki/Kunar_Province), Wikipedia Source: https://taslar.bumba.tr/en/stones/hiddenite/ · Licence: CC BY-SA 4.0