Holiday Return/Exchange Policy: For customers who purchase between now to December 25th, we will automatically extend the return/exchange date to January 31st. No restocking fee, no question ask, hassle free return. Pocket Diffraction Grating Spectroscope It is the same spectroscope that JTV.COM sells for $99 Why Choose USA Seller: No long wait for your order! No additional customs import tax or hangups! More Reliable customer Support! Easy Exchange or return. Top Quality. Pocket Diffraction Grating Spectroscope, with fixed slit fixed focus. Allows you to read a gemstone's spectral signature. Constructed of stainless steel black acetol, 55mm long, 14.5mm wide, and weighs 28 grams. Comes in a protective carrying case. The spectroscope is used to analyze light passing through a stone. White light is a combination of all the colors of the visible spectrum: red, orange, yellow, green, blue, indigo, and violet. This is the rainbow we see when light travels through a prism. When white light travels though a stone, one or more of the wavelengths that produce color are absorbed by the gem. The colors that are NOT absorbed are the colors seen when we look at the stone. The wavelengths that are absorbed by the stone are seen in the spectroscope as vertical black lines in the spectrum. Each stone has a unique absorption spectrum (like a fingerprint of the stone) When identifying a stone we look for a spectrum that is characteristic for that stone. The wavelengths that are absorbed by the stone are seen in the spectroscope as verticle black lines in the spectrum. Each stone has a unique absorption spectrum (like a fingerprint of the stone) When identifying a stone we look for a spectrum that is characteristic for that stone. It comes with a leather carry pouch as shown in the pictures. We offer 2 year warranty. Spectroscope Buying Guide In gemology, there are two different types of spectroscopes, each with its own characteristics. 1. Diffraction grating spectroscope The diffraction grating spectroscope is based on the principle of diffraction. Light enters through a narrow slit and is then diffracted by a thin film of diffraction grating material. This produces a linear spectrum image with a generally larger view of the red part than a prism spectroscope. Inside the diffraction grating spectroscope 2. Prism Spectroscope The prism spectroscope is based on dispersion. The light enters through a narrow slit and is then dispersed through a series of prisms. These models are generally more expensive than their diffraction type cousins. Because prism spectroscopes are based on dispersion, the blue area of the spectrum is more spread out and the red parts are more condensed than the diffraction grating types. Inside the prism spectroscope In conclusion, prism type is better than diffraction type, because it has a larger and more clear image. We have both types of spectroscopes, please click the links below Diffraction Spectroscope (Small Size) Diffraction Spectroscope (Medium Size) Prism Spectroscope We have 2 colors available, Black or Silver. Please leave a message at checkout for your color preference, other wise we will send black color as default. Payments are accepted through Paypal. We ship through USPS Priority Mail from Oregon, west part of the country should receive in 1-3 days,middle part and east part of the country should receive in 2-4 days! International: We charge the same shipping cost to all our customers worldwide(same shipping cost worldwide). Our default shipping is United State Postal Service First Class mail, it take 5-10 business days for delivery. we also offer faster shipping EMS which take 3-6 days. Handing time: 1 business day. For payment received before 14:00PDT, it will ship in the same day. We do Combined Shipment on any multiple purchases. We are pleased to grant a20% discount on the shipping cost of purchases more than item. Please feel free to contact us for discounted shipping costs when you buy multiple items from us. We promise our best quality and the lowest price for our customers, if the item is not as the same as the description in the listing page, we will issue a exchange or full refund. if the item is the same as the description, we will charge a 15% restocking fee. We are a new seller , all our prices are really low compare to others, because we want to earn feedbacks. Please understand our feedback will be left once after we have received feedback from buyer. Our goal is to place a profit margin of $1 ~ $3 per item and sell in volume. As such, the more you save the more we make. While the others are selling 1 item, we are selling 10 ~ 20 items due to our price reduction. Please use the "Ask Seller A Question" button. Please allow up to 24 hours for a response. Usually the buyer will get response in 6 hours.